Volume 1 — GENERAL DISEASES. (continued 8)

Opium or morphia should be used to control pain, excitement, and insomnia, aided, as far as the latter is concerned, by bromide of potassium or the cautious use of chloral. Cooling drinks should be allowed, cool applications made to the head, and the body should be repeatedly sponged with cooling and disinfecting lotions. If the stomach is retentive, quinine in moderate doses may be given in acid solution, alternating with a simple fever mixture; but if nausea and vomiting are present, the first purpose will be to allay them by the appropriate measures already discussed.

Epistaxis is a frequent symptom, but usually requires no special attention. Occasionally it is profuse, and then should be promptly checked, since serious exhaustion may follow its continuance. If, therefore, mild astringent applications do not arrest it, recourse must be had to the tampon saturated with diluted Monsell's solution.

The urine must be closely watched and frequently analyzed in relapsing fever. In some epidemics serious alterations in this secretion are rare; in others it is not uncommon for the urine to be scanty, and to contain albumen or blood. When this latter condition is presented, especially if at the same time uræmic symptoms exist, dry cups should be applied over the kidneys, to be followed by the use of dry heat, and free perspiration should be promoted by hot-air baths or by the hot wet pack. It is probable that jaborandi given in repeated small doses, so as to avoid any depressing effect on the heart, will be found valuable in such cases. Infusion of digitalis, with spirit of nitrous ether or with acetate of potassium, may also be used with advantage.

Absolute rest must be insisted on throughout the entire period of paroxysm and relapse. The records of every epidemic present instances of sudden death from cardiac syncope following trifling exertions. The patients should therefore be kept strictly quiet in bed from the initial rigor until their strength is fully restored after the relapse. As the danger of collapse is especially great at the time of the critical fall in temperature, the patient should be closely watched as the end of the initial paroxysm and of the relapse approaches. If there is any sudden rise of temperature, with head symptoms due to hyperpyrexia, large doses of quinine, ice to the head, cold spraying, or the cold bath must be promptly used. As sweating begins the body must be covered with a warm blanket and warm stimulating drinks be administered. If any marked tendency to collapse is observed, the subcutaneous injection of strychnia or of ether and digitalis, conjoined with diffusible stimulants internally and hot applications externally, are to be employed immediately. The special remedies required for the various complications and sequelæ have already been sufficiently indicated.

I desire in conclusion to acknowledge the important assistance received from Drs. Geo. S. Gerhard, Louis Starr, Charles Shaffner, and R. G. Curtin, who, under the supervision of my colleague, the late Dr. Edward Rhoads, and myself, recorded the histories of most of the cases which serve as the basis of this article, and also tabulated them for statistical purposes.⁴³

⁴³ Reference must also be made to the interesting observations on spirilla published by Mülhaüser in Virchow's Archiv for July 9, 1884, after this article had been printed. His results go to confirm the view that the spirillum of Obermeier is the essential cause of relapsing fever.

VARIOLA.

BY JAMES NEVINS HYDE, M.D.

Variola is an acute, febrile, contagious, and systemic affection, preceded by an incubative period, characterized by the evolution of symptoms in a relatively determinate order, with a cutaneous efflorescence successively papular, vesicular, and pustular in type, followed by crusting, and terminating either fatally or by complete convalescence, with or without sequelæ in the form of multiple, circumscribed, and superficial cicatrices.

SYNONYMS.—Lat., Variola; Eng., Small-pox; Fr., Petite Vérole; Ger., Pocken; Ital., Vajuolo.

HISTORY.—Small-pox is a disease which, there is reason to believe, was first developed in the earliest ages of which the human family has record. Originating probably in China, India, and the adjacent countries of the Asiatic continent, its extension over Europe and America was, without question, in the line of progress pursued by the advancing centres of traffic and population. The earliest traces of its ravages can be dimly recognized in the descriptions of writers in the middle and latter parts of the sixth century. In the early years of the tenth century, however, a remarkably accurate picture of the disease was drawn by Rhazes, a physician of Bagdad. His treatise, translated by Greenhill for the London Pathological Society,¹ sets forth the views of an Egyptian physician named Ahron, who wrote in the sixth century. After these dates the remarkable political and social changes in Europe, which are to be attributed either directly or remotely to the Crusades, contributed largely to the opportunities for the spread of the disease and to the occurrence later of those decimating epidemics which became veritable scourges. In the last century the resulting mortality in some of the countries of Europe was often equal to the entire population of one of their largest cities. If a modern traveller could find himself transported to the streets of the city of London as they appeared in the early part of the present century, it is probable that no peculiarities of architecture, dress, or behavior would be to him so strikingly conspicuous as the enormous number of pock-marked visages he would encounter among the people at every turn. In the face of all cavil and sophistry, medical science will always count among its greatest triumphs the modifications which variola has undergone since its preventive treatment was established upon a satisfactory basis by the discovery of the immortal Jenner.

¹ A Treatise on the Small-pox and Measles, by Abu Becr Mohammed Ibn Zacaríyá Arrází, London, 1848.

The bibliography of the disease is extensive, and the list of authors contributing to the subject is enriched by the names of such men as Boerhaave, Van Swieten, Sauvages, Willan, E. Wagner, Johanny Rendu, Hebra, and, more lately, Kaposi.

ETIOLOGY.—Respecting the etiology of variola, it can scarcely be affirmed that our knowledge has been greatly extended since the date of the experiments of Jenner. There is no historical knowledge of its generation de novo; and the earliest cases of the malady must therefore be classed with the exceedingly rare instances of spontaneous cow-pox which have proved such a boon to the vaccini-culturists. To-day every case of small-pox is justly regarded as having been directly or indirectly transmitted from one or more individuals affected with a similar disorder. It is thus recognized as specifically infectious, contagious, and inoculable, its transmission occurring, first, without contact, by atmospheric conduction of a volatile contagious principle of unknown nature; second, with contact either by (a) actual transference of dry or moist infectious secretions deposited upon a susceptible surface, immediately or through the medium of garments, bed-clothing, paper money, and similar material substances; or (b) by inoculation of unprotected persons with the pathological product of an infected organism. There is no doubt but that the contagious principle displays its greatest activities in connection with the contents of the lesions undergoing a change from the vesicular to the pustular phases, though from the beginning to the end of the disease it is probable that all the tissues and fluids of the infected body are in various degrees capable of producing the malady in those who are unprotected. Furthermore, whether associated or not with an organic substance, the contagium of the disease is known to preserve the power of reproducing itself for a period lasting for weeks, months, and even a longer time. A field for its activities once secured, there is a period of time during which few if any evidences of its progress are declared, this period being abruptly terminated by distinct and characteristic symptoms. This is known as the period of incubation.

The nature of the contagium in small-pox has been the subject of much speculation, careful investigation, and experiment, the results having established but few facts of any practical value. There is at present no proof that any bacteria, vegetable germs, or other minute organisms foreign to the human body are the essential causes of the disease. It is certain that in health the human body is completely enveloped in a volatile medium emanating from the secretions of the glands of the skin, which can be recognized by some of the keen-scented lower animals when it is wafted through the air at a distance of several hundred feet from a single individual. It is reasonable to conclude that not only in small-pox, but in other contagious and infectious diseases, these emanations possess a pathological character, and become capable of transmitting such maladies from diseased to healthy organisms. Certain also it is that when the subjects of these diseases are crowded together, as in prisons, hospitals and camps, this contagious element gathers an unwonted intensity. By far the larger number of all transmissions of variola occur after inhalation of the infective medium—in other words, by the avenue of the lungs. It is probably for the same reason that the disease spreads more widely and with greater virulence during the cold seasons of the year, in this latitude especially from December to February—a time when the ventilation of inhabited dwelling-houses is usually much less perfect than in warmer weather.

The disease affects individuals of all ages and both sexes, not sparing the foetus in utero, and, in the case of the latter, occurring both with and without previous infection of the mother of the unborn child. Nowhere are its ravages so extensive and followed by such fatal results as among those who have long been unprotected by previous vaccination. Among the debilitated, as also among the very young and the very old, small-pox is liable to be followed by severe complications and a fatal result. Negroes, possibly in consequence of tendencies inherited through generations of unvaccinated ancestors, are particularly prone to the disease. Lastly, there is occasionally noted an individual idiosyncrasy, in consequence of which either a remarkable susceptibility to the disease exists or a no less singular immunity against its encroachment is conferred.

Thus, physicians, much exposed to its influences in the discharge of their professional duties, are known to be relatively exempt, while other individuals, few in number it must be admitted, have either had repeated attacks of the malady itself, or, after each exposure to its contagious principle, a recurrent illness of variable type. In the immense majority of all cases, however, one attack confers immunity upon the sufferer against subsequent invasion of the disease for the remainder of life. Upon a few occasions I have known variola to occur in individuals previously affected with cutaneous diseases, especially the eczematous—a fact which merely suggests that such pre-existing disorder of the integument conferred no immunity against infection.

SYMPTOMATOLOGY.—The earliest symptoms of small-pox may be occasionally recognized during the stage of incubation, which, as described above, embraces a period of from ten to fifteen days, though these limits are not absolutely fixed, since both shorter and longer incubative periods have been at times established. During the interval the patient may appear to enjoy perfect health, or, on the other hand, suffer from an ill-defined malaise, with anorexia, languor, insomnia, and allied symptoms. Close observation of the patient thus affected will often reveal the existence of a peculiar pallor of the face, accompanied by a skin-color which suggests a slight degree of sallowness of the complexion. These rather indeterminate symptoms are naturally most marked toward the completion of the period of incubation.

The latter terminated, the period of invasion follows, and extends from the conclusion of the incubative stage to the moment when the first cutaneous lesions of variola appear upon the surface. The symptoms which characterize the onset of this period of invasion are conspicuous and characteristic. There is often a sharp vespertine rigor or a more or less continuous chilliness, accompanied by sensations of "creeping" over the surface, lasting even for several hours. Meantime, the temperature rises to 103° or 105° F., the pulse running up to 120 or 130 beats per minute. In this febrile condition there is commonly complaint of a characteristic aching in the head and back, intense, scarcely intermittent, and so peculiar as to have frequently furnished a clue to the diagnosis of the approaching malady. These sensations are quite analogous to the substernal and other pains which frequently precede the first explosions of syphilis, and are all, without question, due to the circulation of a poisoned blood, the influence of which is in this manner confessed by the nervous system. In the case of infants and young children the invasion of small-pox is frequently ushered in by delirium and convulsions—symptoms which are to be explained by the facts just named.

This complexus of febrile and nervous symptoms, varying somewhat in intensity and possibly interrupted by sensations of chilliness, may be recognized as continuing on the second and third days of the period of invasion. Meantime, there may be noted a dusky hyperæmia of the pharynx and tonsils, the surface of which may even display elevated points which develop later into papules. In exceptional instances the intensity of the poison is such that the system fails to rally before the violence of the onset, and a fatal result ensues before the characteristic exanthem appears upon the skin.

On the second and third days of the invasion stage of the disease, if they are displayed at all, the variolous rashes appear. Too much attention can scarcely be paid to the importance of their recognition on the part of the diagnostician. Often indeed have practitioners been deceived by their occurrence, having been either completely blinded to the serious nature of the malady in progress, or, as Bartholow² has well shown, having supposed that they were dealing with a concurrence of variola and scarlatina or rubeola.

² "The Variolous Diseases," Med. News, Mar. 4, 1882, p. 232.

Hebra was the first to point out the significance of the rash known as roseola variolosa or erythema variolosa. Occurring at about the dates named above, it is in a few patients pronounced and vivid, even in solitary instances rivalling in severity the exanthem which succeeds it. In others, the majority of all patients in some epidemics, it may be entirely wanting. The writer has certainly observed its most typical development in women who were either menstruating or in the puerperal state. It is said also to be relatively frequent in subjects of a tender age. Kaposi³ has recognized it in all its manifestations at every age.

³ Consult the admirable chapter on variola in his treatise, Path. u. Therap. der Hautkrankt, Wien, 1882.

It appears in the form of puncta, striæ, or diffuse and uniform blushes covering extensive areas of the integument, livid red, purplish, or brownish-red in hue, paling under pressure, but never leaving upon the skin over which the finger-nail is quickly drawn the characteristic whitish streak by which many practitioners test the scarlatinal rash. The surfaces involved may be either not raised or slightly elevated above the general level of the skin, and are usually circumscribed. The regions chiefly involved have been carefully described by Th. Simon, and are hence sometimes called Simon's triangles. Thus the groin, the internal face of the thighs, and the hypogastric region may be involved at once (femoral triangle of Simon); the surface of the axilla, the pectoral region, and the inner face of the arm (brachial triangle of Simon), as also the extensor faces of the knees and the elbows, the dorsum of the feet, and indeed every portion of the surface of the body.

In the midst of these rash-covered areas may also appear petechial or hemorrhagic, dark-red, pin-head to bean-sized maculæ, which undergo color-changes both in lighter and deeper shades as the invasion period lapses. In lieu of these, however, transient wheals may come and go over the surface, and even the erythema described above may assume an erratic phase and appear in one part only to disappear and recur at another. None of these flash-light warnings of the oncoming exanthem are proportioned to the latter in the matter of extent and intensity of development. They may be followed by grave or mild manifestations of the disease. The subsequent eruption may also be much more abundantly developed in regions where the invasion rashes have not appeared, and the latter completely fade before the former have advanced to occupy the field thus deserted.

The invasion stage of variola commonly occupies three days. Rarely it extends into the fourth, fifth, and even the sixth, day after the premonitory chill and fever.

Upon its subsidence the exanthem of the disease as a rule promptly appears. Simultaneously, the temperature abates, the rapidity of the pulse diminishes, and there is marked amelioration of the general symptoms. The patient, frequently deceived by the completeness of this defervescence, is apt to conclude that he is convalescent from his disorder, and is thus often astonished at the discovery of the exanthem upon the person, usually the face. In other cases, more commonly those of a grave character, there is failure of this defervescence, the febrile symptoms continuing or even increasing in severity.

The eruption first appears in the form of pin-head sized and larger, firm, conical, discrete, coherent or confluent, reddish papules, sometimes accompanied by mild sensations of a pricking or painful character, often exciting no subjective symptoms by which their presence could be declared. To the touch they are characteristically indurated, and suggest the hardness of small shot imbedded in the skin. They appear first and in greatest abundance upon the face and scalp, involving later and progressively the trunk, the extremities, and the palmar and plantar surfaces. It is at this moment that the eruption most resembles that to be recognized in measles (the distinction between the eruptive symptoms of the two diseases will be considered later). At times a reddish areola surrounds each lesion, especially those appearing upon the trunk. All are situated about the orifices of the follicles and glands of the skin.

On the first and second days of the eruption the papular lesions multiply in number, involve an increasingly large area, and individually augment in size; so they appear first upon the head, and are successively presented to the eye upon the lower portions of the body. The older lesions are usually recognized upon the scalp, face, neck, and shoulders; the more recent upon the extremities. By the third day of the eruptive stage there is usually evident at the apex of the older lesions a minute vesicle containing a drop of pellucid serum, which rapidly changes in character and size till a distinct vesicle is formed with cloudy or lactescent contents. Early in their career an apicial depression can be seen, which later deepens into a characteristic umbilication. This umbilication in the vesicular stage is somewhat peculiar. It is more than a mere depression of the summit, such as might be made by thrusting a blunt-pointed pin centrally and downward so as to carry the roof-wall before it. It is made clinically most distinct by the fluting or puckering of the peripheral part of the roof-wall, giving the lesion a crenated appearance which is not assumed by any other cutaneous efflorescence of multiple development. It may be regarded as pathognomonic of variola.

The pock is usually mature by the sixth day of the eruption. It is pea-sized and globular in shape; its umbilication has been usually quite removed by the complete filling of its chamber with distinctly purulent contents; it is often surrounded by a halo due to hyperæmia or exudation; and, the total number of individual lesions being then fairly determined, it is often closely set against its fellows, islets of unaffected integument having meantime become fewer and more contracted. The face, covered with this eruption, then exhibits a typical aspect. The entire integument becomes swollen and brawny or oedematous. The eyes are thus closed by the tumid lids, which are separable with difficulty, and this, too, even though they be the seat of comparatively few lesions. The nose, lips, cheeks, and ears are by similar processes deformed and given a most repulsive unsightliness. Mucus and puriform secretions gather and dry about the mucous outlets. The skin of other parts of the body (hands, feet, genitalia, and the entire extremities) is in a similar condition, merely most noticeable in the exposed and disfigured visage.

The fever of maturation or suppuration, or, as it is often called, the secondary fever, is lighted to activity with the onset of the suppurative process. The temperature rises to a point ranging between 101° and 105° F., the pulse-rate simultaneously rising to 100 and even 150 in the minute, varying of course with the age of the patient and the severity of the attack. During its continuance, from the eighth or ninth to the eleventh or twelfth day of the disease, the victim of the malady is in a deplorable and critical condition. The intense grade of cutaneous inflammation, with its resulting subjective sensations of burning pain and tension, the soreness of the mouth (tongue, pharynx, inside of lips, and palate), due to the existence of pus-filled pocks upon the buccal membrane, and, for similar reasons, the dysphagia and irritation of the larynx and tracheal membrane, are all sufficient to account for the general condition. In cases of mild grade the patient lies conscious, but in a stolid apathy, listlessly accepting the services of his attendants. In others there is delirium of low or high grade, often sufficient to demand constant surveillance, lest in consequence the patient do serious injury to himself.

The behavior of the pustules which appear upon the mucous surfaces accessible to the eye is modified somewhat by the heat, moisture, and friction to which these surfaces are exposed. Typical, fully-distended pustules occasionally persist upon the soft palate and the inside of the lips. Soon, however, the macerated roof-wall yields, leaving a reddish floor where the mucous membrane is exposed, denuded of its epithelial layer or covered with a new tender and hyperæmic pellicle. In grave and severe cases these pustular lesions may extend deeply into the mucous tracts, involving the trachea, bronchi, or alimentary canal. In an autopsy made by the writer on the body of a male subject dead of unmodified variola, there was no portion of the alimentary canal from the mouth to the anus which was not studded by thickly-set pustules. The urethra, vagina, vulva, external auditory canal, and conjunctivæ are, in severe cases, similarly involved. According to Kaposi, the tympanum is usually exempt.

The period of desiccation begins usually on the thirteenth or fourteenth day of the disease, and, according to the severity of the previous pathological processes, requires for its completion from one week to a fortnight. Its onset is characterized by a second marked but gradually developed defervescence. With a diurnal temperature successively less elevated above the normal standard there is a corresponding fall of the pulse-rate. As the disease has by this date taxed the vital resources of the system to the utmost limit, the exhaustion resulting may be declared by a pulse which is flagging, weak, and even in the matter of frequency much below the standard of health.

The cutaneous lesions now again undergo a change. Some of the pustules rupture, and their viscid contents, oozing forth, concrete into a yellowish crust which gradually assumes a brownish hue. Others desiccate en masse, the roof-wall first collapsing upon the contents, thus producing an appearance which again suggests umbilication of the lesions. This is sometimes termed a secondary umbilication. The desiccation en masse is doubtless due to the evaporation of a portion of the fluid exuded into the superficial strata of the integument, and the consequent inspissation of the pus. Often the face at this moment is totally concealed by a dense, dry, brownish or even blackish mask, composed of the crusts furnished by numerous individual lesions. At the same time the tumefaction of the skin subsides, and the subjective sensations to which it gave rise gradually disappear. Beneath the crusts cicatrization advances till the former are lessened, and finally, becoming detached, fall in quantity from the surfaces subjected to friction. Beneath them are seen brownish and violaceous blotches, the integument thus stained slowly losing its abnormal color. It is thus seen to be the seat of multiple, slightly depressed, shining scars of a dead white color, which in the course of time lose somewhat of their disfiguring prominence, but which when typically distinct persist for a lifetime. This exfoliation of crusts continues till the skin is completely rid of its pathological products, the process being completed with entire restoration to health about the conclusion of the fourth or fifth week of the disease. Meantime, in favorable cases, convalescence progresses pari passu. The patient has a returning appetite, decadence of symptoms originating in impairment of function of the mucous membranes, and gains in weight till the restoration to sound health is complete.

Such is the history in outline of what may be regarded as a typical form of uncomplicated variola. It should not be forgotten, however, that in different epidemics there are marked differences in the career and manifestations of the malady, and that even among the cases observed in a single locality visited by the disease the same divergence of symptoms is no less conspicuous. This diversity is due to several causes, irrespective of the remarkable modifications displayed in the variolous who have been previously vaccinated. Individual susceptibility is doubtless to be considered in this connection, as also the temperament, bodily vigor, and hygienic surroundings of those who are infected. It is possible also that the intensity of the poison may be subjected to occasional modifications in its transmission from individual to individual. In this way the following types of variola present themselves in clinical forms with divergent features:

CONFLUENT VARIOLA (variola confluens).—This virulent form of small-pox is ushered in by a relatively short incubative period, followed by a severe invasion of the disease. The premonitory chill is violent; the cephalic and lumbar pains are excruciating; the fever, rising to a high grade, 106° to 110° F., with few and slight remissions, scarcely subsides, if at all, with the appearance of the eruption, the latter developing early, and, to borrow an expression from syphilographers, exploding with violence over large areas of the surface of the body. The initial lesions of the exanthem are dense and deeply-set papules, so closely coherent even at this moment that they scarcely leave between them interspaces of sound skin. During the vesiculo-pustular transformation which they promptly undergo on the second day there is a more or less complete coalescence of the elements of the eruption, which circumstance has given this form of the disease its name, confluent variola. This confluence is most conspicuous upon the face and hands, where large flat vesicles run together, form pus-filled bullæ, and finally convert the surface on which they rest into a single, large, many-chambered pustule. All this occurs upon an enormously swollen and inflamed skin, disfiguring every feature of the face and wellnigh obliterating every external distinction between the scalp, nose, eyes, and mouth. Here and there the mass is elevated by the quantity of exuded pus to a more notable projection from the surface. Pustules filled with blood may appear at several points. At others, the suppurative inflammation may be seen to have eroded the derma, which is covered with a diphtheritic membranous exudation similar to that covering the mucous membranes lining the mouth, nose, and ears. Naturally, the skin in its totality often yields to these destructive processes and in large patches falls into gangrene.

The confluence of the lesions is less marked in other parts of the body than the face and hands, yet the entire surface may be covered with a coherent exanthem which becomes elsewhere, in large areas, confluent. The writer has seen patients in whom the head of a pin could not be placed upon an unaffected patch of skin in any portion of the body. The parts subjected to pressure in the reclining posture, such as the back, shoulders, and buttocks, are especially liable to this coalescence of the pustular lesions.

In confluent variola too, as already intimated, the mucous surfaces suffer proportionately. Pasty accumulations of muco-pus and diphtheritic exudation, like macerated chamois leather, cover the tongue, which is often so enormously swollen as to bulge between the teeth and project from the mouth. These exudations line the mouth, pharynx, larynx, and even the bronchi. Beneath these masses the eroded mucous surface is dry, livid red in color, and has a varnished aspect. Gangrene here may lead to necrosis of the cartilages of the larynx. Aphonia is often complete, deglutition impossible, respiration difficult. The stench arising from the patient is intolerably fetid and pervading, and a single exhalation will poison the best-ventilated apartment. The submaxillary and sublingual glands are enlarged and the neighboring lymphatics swollen.

The patient who is plunged into this grave condition is the victim of a fever which is unquestionably septicæmic in character; he has a small, frequent, and often fluttering pulse; his mental condition is betrayed by a delirium of varying grade or he lies comatose. In this state a fatal result is often induced by either exhaustion of the vital forces or an intercurrent malady, such as pleurisy, pneumonia, cardiac inflammation, oedema of the glottis, or an uncontrollable diarrhoea. In yet other cases the patient falls into a typhoid state, and, after surviving for a fortnight or more with a low fever, a broncho-pneumonia, or a diarrhoea, succumbs to an inevitable exhaustion, the surface of his body being yet covered with a dry, blackish, and fetid crust.

The expression of an intense variolous poison is known as hemorrhagic variola; also as purpura variolosa and black pox. A large number of such cases have been designated and treated as black measles, the real nature of the malady having been mistaken.

The law readily observed by the diagnostician of diseases in general must here be recognized. There are no hard and fast lines in nature. Hemorrhagic variola occurs, without question, in different types. At the one extreme are classed the inevitably fatal cases, where the patient sinks smitten by the malady even before the exanthem is developed; at the other are found the cases of confluent variola, not necessarily fatal, in the course of which hemorrhagic lesions appear in variable number, blood either filling the pustules after the latter have arrived at maturity, or forming ab initio purpuric pocks intermingled with the typical lesions of the variolous exanthem. However ill-defined the limits between these classes may be, the symptoms of hemorrhagic variola are sufficiently characteristic to require separate description. According to Kaposi, it occurs in the two following types:

The first form is termed variolic purpura. Its incubative period is brief and distinguished by unusual conditions of malaise and lumbar pain. On the fourth day there is an intense fever with rapid pulse, and this is speedily followed by a deep purplish-red staining of the face, neck, trunk, and extremities, the skin thus affected being slightly tumid and quite dry. Minute maculo-papules can be distinguished here and there over the surface, often closely set together, and presenting the characteristic color described above. At this stage of the disease the eruption greatly suggests an intense rubeolous exanthem, and has been, as a result, repeatedly mistaken for the so-called black measles. But the excruciating pains persist, there is often coincident delirium, and the pin-head sized maculo-papules noted above become lenticular in shape, cease to lose their color under the pressure of the finger, extend peripherally even in a few hours, flatten and become purpuric patches of a bluish-black shade, palm-sized and even larger, covering extensive areas of the integument, new lesions forming in unaffected islets of the skin; conjunctival ecchymoses appear at the angles formed by the lids, and finally encircle the cornea with an annular purplish-black cushion. The mucous surfaces become dry, crack, and bleed where the epithelium is torn, and become covered with offensive crusts. The odor exhaled by the patient is intolerably fetid. He lies stupid as the march to a fatal issue is hourly hastened. Hemorrhages occur from the larynx, bronchial membrane, intestinal surfaces, and even into the parenchyma of the viscera, the muscles, serous membranes, periosteum, and neurilemma. The urine is retained in the bladder; the respirations rapidly increase in frequency; the pulse flutters; and death closes the scene between one and two days after the onset of the malady. In several cases observed by the writer, occurring in infants and children, the entire course of the malady was completed in twelve hours.

In the second and much rarer form of hemorrhagic variola there are the usual unfavorable portents of intense prodromic symptoms. On the fourth day the skin is swollen and indurated in consequence of the development within its structure of numerous firm, roundish, slightly acuminate papules, so thickly set together that it is wellnigh impossible to distinguish between them. These are early in betraying the bluish-black hue significant of hemorrhage into their mass. They multiply in number and increase in size, while their hemorrhagic stains widen and sweep from each as a centre, like the waves that spread from a pebble thrown into smooth water. In these cases, more often than in those first described, pus-filled pocks may develop over some portions of the surface, while in others a species of gangrene occurs in consequence of the separation of the derma from the subcutaneous tissues by effused blood. At times pustules of somewhat typical aspect are formed and subsequently filled with blood by a hemorrhage from below. The accompanying symptoms are grave, but less rapidly fatal than in the other types of the disease. Delirium, stupor, an intense fever, and a rapid, feeble pulse are commonly noted. A fatal result is usually reached in from four to five days.

Hemorrhagic lesions, isolated or confluent, are seen also in severe forms of variola, not of the two types described above. Thus, in confluent small-pox, especially when occurring among the unvaccinated, some of the pustules on the face, the back, or possibly the legs, where varicosities of the veins permit a passive engorgement of the tissues with blood, may become the seat of a hemorrhage. For these local causes are often etiologically effective. In other cases the appearance of the hemorrhagic lesions seems to be due to a dyscrasia, such as that recognized in phthisis, chronic alcoholism, and hæmophilia.

Aside from the trivial accidents to which the exanthem may be subject, the hemorrhagic types of variola may be regarded as necessarily grave and in a large proportion of cases inevitably fatal. That they are all truly the results of variolous poisoning is shown, first, by the occurrence of intermediate forms; second, by the occasional transmission of the disease in its typical aspects to the partially protected.

VARIOLOID is that form of variola in which the disease is modified, either in its course, duration, or intensity of symptoms, such modification usually resulting, directly or indirectly, from the protective influence of vaccination or from a previous attack of variola.

The symptoms of the class of patients commonly regarded as suffering from varioloid are all those of variola, modified, however, in the direction of a mitigation of their intensity and dangerous character. It is thus evident that there is no strict line of demarcation between the very mildest physical expression of the variolous poison and that variola vera which presents atypically benign symptoms in any stage of its career. Within this wide range of possibilities cases of varioloid occur which certainly differ from each other by very marked degrees.

The invasion stage of varioloid may be shorter or longer than that occurring in variola vera, and may be insignificant or intensely marked as regards the severity of its symptoms. According to Bartholow⁴ the invasion rashes are here of common occurrence; and the more extensive the latter, the less copious the subsequent eruption. It must be admitted that a personal experience has not confirmed us in this view.

⁴ Loc. cit.

After the high fever and severe cephalic and lumbar pains of this stage there may follow, in the case of varioloid, a complete defervescence and the appearance of a very copious exanthem. With this, however, the apogee of the disease may be reached, and the subsequent symptoms be altogether insufficient in comparison with those which have preceded. Thus, the maculo-papules may never reach a vesicular stage, or, having attained this, the vesicles may not be umbilicated, or may shrivel after their contents have assumed a lactescent color, and be succeeded by light superficial crusts which in a few days fall. Or, again, the pustular stage of the lesions may be fully developed, even with the production of a halo about the pocks, while yet there is no swelling of the skin and but trifling subjective sensations experienced by the patient. The pustules in the course of from four days to a week desiccate and are shed, leaving behind them violaceous pigmentations of the surface without persistent cicatricial sequelæ.

Other cases, again, instead of producing the impression upon an observer of being illustrations of a malady aborted or cut short at some period of its career, seem to exhibit merely a modification in the intensity or distribution of symptoms betrayed in a wellnigh typical career. Thus, there may be a total absence or insignificant reminder of the septic fever usually known as the secondary fever of variola, and the elements of the eruption may be few or appear in scanty number upon the face and more copiously elsewhere. The latter may, however, pursue a perfectly typical career and be followed by characteristic scars.

There is yet another type of varioloid with which many practitioners become familiar who have experience in epidemics of small-pox. The patient exhibits distinct symptoms of malaise in the period of incubation. The fever of invasion, with its characteristic pains and nausea, is equally well marked. Defervescence occurs with a trifling eruption of maculo-papules, which in two days have wellnigh completely disappeared. There is no secondary fever, but the patient is far from well. There is a period of anæmia, mental depression, marked languor, and unmistakable evidences of physical prostration out of all proportion to the precedent symptoms. In these cases it may well be believed that the poison has at last produced a strong impression upon the nervous centres. The most characteristic feature of these cases is the tedious convalescence from an apparently trifling form of the malady.

The identity of varioloid with variola is abundantly shown—first, by the occurrence of intermediate forms of every grade, from the mildest evidence of variolous poisoning to typically developed cases of variola vera; second, by the fact that patients affected with varioloid are capable of transmitting variola to the unprotected; third, by the anatomico-pathological fact that the structure of the pock, when it appears, is the same in all.

A variation as to the form and contents of the lesion of modified variola occasionally occurs as a consequence of individual peculiarities or of the special surroundings of the patient. A number of useless terms have been employed to designate these peculiarities, the most of which are relics of the superstitions of the past. In variola siliquosa the pocks are said to contain air only; in v. pemphicosa, bullous lesions predominate; in v. verrucosa, the papules, after partial evolution and involution, leave minute wart-like papillary masses upon the face; in v. crystallina, there are superficial vesicles only filled with clear serum, which somewhat resemble those recognized as sudamina. The older English writers with as little reason described cases of horn-pox, swine-pox, etc., differing only from those of variola by the anomalous behavior of the exanthem in the course of its evolution.⁵

⁵ Besides the terms given above, Hebra gives the following list of Latin adjectives which have been employed to describe special varieties of small-pox, none of which requires special explanation: variola papulosa, conica, acuminata, globosa, globulosa, tuberculosa, cornea, fimbriata, miliaris, lymphatica, vesiculosa, pustularis, rosea, morbillosa, carbunculosa, etc.

COMPLICATIONS AND SEQUELÆ.—The complications and sequelæ of variola are fewer in number and more restricted in range than those of many other maladies. This results from the remarkable unity of the disease as it occurs in its several manifestations among the unprotected, its relatively rapid progress, and its absolute disappearance on the completion of its curriculum. There is no chronic form of variola lingering for weeks and months after the violence of the fever has abated.

Furuncles and abscesses occasionally result during or after the pustular stage of the disease has been reached, sometimes of such extent as to give exit to large quantities of an ill-conditioned pus. The tissues, weakened by the suppurative process which the skin has undergone, may then necrose, and thus lay bare periosteum, cartilage, or bone. Erysipelas, especially about the face, may close the eyes, encroach upon the scalp, or spread extensively over other regions. Muscular paralyses, hemiplegic and paraplegic attacks, albuminuria, diarrhoea, and the inflammations of chronic type affecting the thoracic organs may each supervene, and either greatly prolong convalescence or precipitate a fatal issue. None of them is perhaps more common than a low typhoid and febrile state, in which the patient lies after his variola is practically ended, his skin struggling to regain its normal tone, a fever of remittent type taxing his energies, his bowels in frequent movements discharging a thin and fetid feculent matter, while a low delirium renders him insensible to the gravity of the situation.

Reference has been made above to the implication of the eyes of the variolous, and the possibility of the disorder terminating, after an otherwise favorable convalescence, in total blindness, should not be forgotten. The cornea may be the seat of pustules or a diffuse puriform infiltration resulting in ulceration, and eventually perforation with hernia of the iris. At times it is merely macerated by the pus continually covering it, and in that condition yields to even moderate pressure. At others the deeper portions of the globe fall into inflammation, and there is a resulting cyclitis, irido-cyclitis, or parophthalmia.

In the nose severe destructive effects may follow the pustular involvement of the Schneiderian membrane, including necrosis of the nasal bones and profuse epistaxis.

In a similar way, the external ear may be involved, the tympanum disappear, a severe otitis media supervene, and the mastoid cells become filled with pus and detritus of necrosed tissue.

In the larynx, which may be well lined with pustules, as indicated above, complications may arise in the shape of oedema of the ary-epiglottic folds,⁶ laryngo-oesophageal abscess and various diphtheritic deposits lining every portion of the mucous membrane.

⁶ J. William White, "Surgical Aspects of Small-Pox," Medical News, March 4, 1882, p. 241.

Other disorders noted as complicating variola are hydrocele and orchitis in the male, ovaritis in the female, gangrene of scrotum or labia, hæmaturia, peritonitis, adenopathy and lymphangitis and arthritis, as well as peri-arthritic suppurative inflammation.

PATHOLOGY AND MORBID ANATOMY.—Ours is a day in which bacteria, special to each of a number of infectious diseases (lepra, pemphigus, tuberculosis, etc.), are constantly reported as coming to light under the persuasive influence of modern staining solutions. With respect to variola, it may be said that while Cohn, Klebs, Weigert, and others have, without question, recognized microsphæra, micrococci, and similar organisms in variolous pus, their causative relation to the pathological process has certainly not yet been demonstrated.

The pathological anatomy of the cutaneous lesions of variola has been very carefully studied by Auspitz and Basch,⁷ and Heitzmann.⁸ The following is a condensed account of the results reached by these observers:

⁷ Virch. Archiv, Bd. 28.

⁸ Trans. of Amer. Derm. Ass., Aug., 1879.

First appear circumscribed patches of hyperæmia, in which the papillary layer of the corium is concerned, and which is followed by some thickening of the rete, the epithelia involved becoming coarsely granular. This granular condition is due to an increase of living matter within the protoplasmic bodies, evident at the points of intersection of the reticulum of which they are composed, the nuclei becoming solid and shining, and the threads traversing this cement-substance between them becoming also increased in thickness. The papillæ beneath increase in size in consequence of their vascular engorgement, and in consequence of the change experienced by the connective-tissue bundles, which are partly transformed into protoplasm, while the protoplasm between them increases also. There is, in brief, a liquefaction of the glue-giving basis-substance, which makes visible the reticulum of living matter formerly hidden within it. In this way the epidermis is raised into the flat solid papules which are the early lesions of the disease.

Then follows an exudation of a serous fluid at one or more points in the papule, the meshes of the reticulum being so stretched and torn that small chambers are formed filled with the liquid exudate containing granules. Between these chambers the separating strata of epithelia are compressed so as to form septa or partition walls. The neighboring epithelia become granular, divested of their cement envelope, and transformed into protoplasmic clusters still connected with the living reticulum by slender threads. An irregular cavity is thus formed in the thickened rete traversed by septa, the contained exudation being filled with granules, coagulated fibrin, and lymph. A few protoplasmic bodies are here also distinguishable, which Heitzmann regards as either débris of destroyed epithelia or colorless blood-corpuscles.

In these changes the connective-tissue beneath participates. The papillæ eventually disappear, the superior portion of the corium being replaced by clusters of medullary or inflammatory elements uninterruptedly connected by threads of living matter.

The pus-corpuscles which eventually appear originate mainly from transformed epithelia. In the process of transformation the increased protoplasm of the epithelia first exhibits shining homogeneous lumps, which, after an intermediate stage of vacuolation, undergo an endogenous metamorphosis into nucleated bodies with a reticulum in each. To the number of these there is possibly an addition by the immigration from below (diapedesis) of leucocytes.

The question of repair with or without the production of cicatrices rests upon the behavior of the connective-tissue elements. If these are not torn asunder, but remain in connection with each other, the re-formation of a glue-giving basis-substance is possible, and new bundles of fibrous connective-tissue take the place of the old. If, on the contrary, the latter are completely destroyed, their place is filled with the cicatricial new growth. The pigmentation, which is such a common transitory sequela of the skin lesions, is due both to the imbibition of the coloring matter of the blood by the epithelia and by direct hemorrhagic exudation into both the rete and derma.

The umbilication of the mature pock is doubtless due to the situation of such lesions at the orifices of the excretory ducts of the skin-glands. The epidermis, in one or more of its strata, dips downward to form a living investment for such glands, and in this situation ties down the centre of the roof-wall of the pustules. Eventually, it too, as a result of the maceration and tension incidental to the complete filling of the pock with pus-elements, is ruptured or stretched, and the umbilication of the pustule disappears.

The anatomy of the exanthematous lesions in hemorrhagic variola is not different from that described above. The pocks in such cases are merely filled with blood instead of with pus or sero-pus. In some forms of hemorrhagic variola, as indeed would be suggested by their clinical observation, there is hemorrhage directly into the tissues of the integument, or, more probably in severe cases, a mere passive leaking of the sanguineous fluid with its coloring matter through the relaxed and weakened vascular walls.

The morbid changes occurring in the viscera are described by Curschmann as follows: The mucous surfaces may be the seat of pustules, diffuse purulent infiltration, and catarrhal, croupous, or diphtheritic inflammation. As regards the extent of diffusion of the pustular lesions, they occur, according to Wagner, in bronchi of the second and even of the third order, rarely in the stomach and intestines, and in the rectum only in its lowest portion. The bladder, urethra, and serous surfaces are always exempt. The lungs, breast, liver, spleen, brain, and spinal medulla are variously involved. Often the tissues of these organs are quite unchanged as regards their macroscopical appearance. At other times the tissues appear swollen, granular, and undergo a fatty degeneration. In purpura variolosa the spleen and walls of the heart, however, are seen to be firm, dark-red, and more or less indurated.

DIAGNOSIS.—The establishment of a correct diagnosis where there is question of variola is one of the most critical and important of the duties of a physician. Upon such decisions have turned, again and again, professional success or disaster. To pronounce that case to be variolous which is not of such a nature is to subject one to the indignation of the few and the ridicule of the many. On the other hand, to be guilty of treating a patient with small-pox, and of remaining ignorant of the nature of the malady, is to subject many ignorant people to the danger of exposure to the disease and to render one's self liable for the redress sought by recourse to the civil authorities and the law. It is difficult to decide which predicament is the graver.

Typical variola vera is readily recognized by its characteristic features. As usual, it is the atypical and modified forms where the difficulty most often arises and where the danger to the physician is proportionately increased.

In the invasion stage of the disease it is often impossible to recognize any symptoms characteristic of variola. High fever with severe lumbar pain, considerable gastric distress, and the appearance of one of the invasion rashes (roseola variolosa) would, however, put the observant practitioner on his guard. I have often noticed in these cases a symptom which, apparently insignificant, has on more than one occasion preceded the eruptive period. It is the occurrence upon the centre of the two cheeks of a vivid damask-red blush, occasionally having a purplish-red hue, and with a very remarkable circumscribed area. This may be recognized in children and adults of both sexes when it occurs in typical aspect, and is undoubtedly a hyperæmia of the character of that producing the rashes in Simon's triangles.

When the variolous exanthem first appears the practitioner should secure as soon as practicable a history of the invasion stage if this has not been subject to his personal observation. He should then make careful inquiry as to the possibility of a neighboring source of contagion, and ascertain by inspection whether the person of the patient exhibits the evidences of successful vaccination. In this connection it is always well to estimate the value of the elements represented by (a) the period ascertained as having elapsed since the last successful vaccination; (b) the typical or atypical character of the existing cicatrices of vaccinia; (c) the unicity or multiplicity of the cicatrices simultaneously resulting from vaccinations performed at one and the same date.

Without question, the first papular lesions of variola resemble those of rubeola or measles to an extent which has often deceived the most expert diagnosticians. The distinguishing points are—(1) In measles, catarrhal symptoms (conjunctival, nasal, laryngeal, bronchial), which are usually absent in the early stages of variola, and later are obviously associated with the irritation set up of the pustules of the maturing period. (2) The difference in the temperature record, that noted in the invasion stage of variola varying from 104° to 105° F., while in rubeola it is rarely registered above 103° F. Moreover, in typical variola the defervescence is marked and characteristic on the appearance of the exanthem, while in rubeola, when the rash appears, the temperature is usually sustained at a maximum, and may even rise. (3) The differences in the rashes of the two disorders. The papules of variola, even in its confluent forms, are, when first observed, remarkably discrete and exhibit not the slightest tendency to grouping, while the maculo-papules of rubeola are (a) developed simultaneously on the face and trunk, while those of variola commonly appear first on the face and afterward on the trunk, the older, and larger therefore, in the site of earliest appearance; (b) are set in clusters or groups having a distinct tendency to crescentic arrangement, a symptom decidedly best appreciated by the eye when the eruption is viewed in totality or in large areas with the eye of the observer somewhat removed from the surface; (c) are often made to disappear or pale beneath the pressure of the finger, while there is greater persistence of color in the variolous papules; (d) are surrounded by little or no halo, each elementary lesion of the eruption being abruptly defined upon the sound skin, while the variolous papule is apt to rest upon a circlet of hyperæmic integument.

Even with careful observation of all the specific differences between the two diseases, they may, for a brief time, so resemble each other as to defy the skill of the expert. In all doubtful cases the physician should invariably admit the doubt and defer an exact diagnosis for twenty-four hours. During the delay the variolous exanthem should betray its individuality by the formation of a minute vesicular apex at the summit of several papules.

In scarlatina the uniform diffusion of the exanthematous blush, the absence of papules and vesico-papules, the continuance of the fever after the rash has appeared, the characteristic scarlet or boiled-lobster color of the skin, and the anginose condition of the throat, are all significant symptoms. In hemorrhagic small-pox the color of the integument is a much more purplish and lurid-reddish hue, rapidly reaching that stage where it refuses to pale under the pressure of the finger, and never leaving in the track of the finger-nail quickly drawn over its surface the peculiar transitory yellowish-white line which can be usually obtained in the skin of the patient with scarlatina.

The pustular stage of variola might be confounded with the pustular syphiloderm. But in the latter there should be a history of a chronic rather than of an acute affection, and, as a result, the simultaneous appearance of lesions in very different stages of their career, some distended with pus, others ruptured and crusted, yet others which have recently formed in the immediate vicinity of the oldest lesions, while the latter have been in full involution or have been replaced by superficial losses of tissue.

The resemblance of pustular variola to certain suppurative and other disorders of the sebaceous glands is well attested by the name given by certain French authors to molluscum epitheliale (M. contagiosum, M. sebaceum)—viz. acne varioliformis. But in the case of acneiform disorders the concurrence of comedones, the chronic course of the disease, the absence of fever and systemic disturbance, and the particularly irregular distribution of the lesions upon the face, with failure to appear elsewhere,—all these facts forbid the confusion of the affection with variola. In medicamentous acne, accompanied by the sudden appearance of numerous pustular lesions symmetrically displayed upon the surface, there will indeed be a source of error. In such cases, of course, a history of the ingestion of a medicament capable of producing a rash will afford valuable aid in the diagnosis. In pustular forms of dermatitis medicamentosa there will usually be found a more abundant development of the pus-containing lesions upon the head and both arms and forearms, with no tendency to extension over very large areas of the trunk and lower extremities—a circumstance which a delay of but a few hours will often substantiate.

The absence of marked defervescence is the most characteristic difference between variola in its eruptive stage and typhus, typhoid, and relapsing fevers. Pneumonia, cerebro-spinal meningitis, acute miliary tuberculosis, and gastric fever are all to be differentiated from variola by the occurrence of symptoms characteristic of the involvement of the several organs which in these diseases respectively are more particularly impaired.

PROGNOSIS.—The prognosis of variola is wellnigh inseparably associated with the question of protection by vaccination. Variola vera in the unprotected is an exceedingly fatal malady, the death-rate varying in different epidemics according to the severity of each and the ages and hygienic surroundings of the victims of the disease. Certainly, from 15 to 50 per cent. of unprotected individuals affected with the disease occurring in epidemic form in any given community will perish. This number may, however, be enormously increased, as, for example, among a large number of unprotected negroes crowded together in a filthy prison, or when the malady makes a periodical visitation to an insular community where long isolation has begotten a carelessness with respect to vaccination.

With respect to individual cases it may be asserted, first, that an intense series of prodromic symptoms, followed by the appearance of an unusually large number of cutaneous lesions, is often unfavorable. Confluence of the latter adds to the gravity; hemorrhagic and purpuric symptoms are in the highest degree portentous, and commonly indicate a fatal result. Women pregnant or in the puerperal state, infants at the breast, and persons of both sexes at advanced ages, are little able to resist the ravages of the disease. According to Kaposi, women recently delivered prematurely or who have lately suffered from an abortion succumb more often than others of their sex. Chronic alcoholism among male subjects and the cachexia induced by all chronic visceral and systemic disorders are sources of weakness which largely increase the death-list by adding to the heavy strain upon the vital energies. The prognosis is rendered uncertain or unpromising by extensive involvement of the mucous as well as of the cutaneous surfaces, by marked visceral complications, by evidences of shock or exhaustion before the apogee of the exanthem is reached, by grave sequelæ, and even by simple complications of the malady when, instead of entering promptly upon convalescence, the patient lingers for weeks in a typhoid condition. An unfavorable symptom in any case is the sudden cessation of the processes actively pursued upon the surface of the body. The swelling of the integument then suddenly diminishes and the crusts by which it was covered shrivel. The eruption, in brief, seems to undergo what may be described as a collapse. The pulse at such moments usually flutters feebly, and there are other portents of dissolution which the eye of the physician will hardly fail to interpret correctly. The fluids in such instances mechanically drain away from the surface of the body to seek the deeper parts. This is not peculiar to small-pox. Similar phenomena occur even in the case of other than exudative affections of the skin. In pityriasis rubra the patient dies leaving an integument apparently unaffected, and I have seen a patient dead of even multiple sarcoma of the skin when the tumors were reduced fully one-half in bulk as the result of a similar cause.

On the other hand, the practitioner should never forget that even apparently desperate cases of variola rally and are won back to life. That the exudative process should be in full evolution at the surface of the body is, cæteris paribus, certainly so far a good omen. The most hideous, extensive, and stench-emitting crusts have hidden for a time the forms that have for many subsequent years not only known the enjoyment of life, but have made that life of inestimable value to others. The physician in the presence of this most loathsome and formidable disease should never despair.

PROPHYLAXIS AND TREATMENT.—The loftiest end to be reached by the physician of our day with respect to variola is its complete removal from all civilized countries, and indeed from the face of the earth, by the practice of universal vaccination and revaccination. The evident modifications which the disease has undergone in late years as a consequence of the extraordinary attention given to this subject is an earnest of the future. The day is probably not far distant when the man, woman, and child unprotected by vaccination will properly be regarded as an enemy of the human race, and treated accordingly. Evidences of the most satisfactory character as to successful vaccination should be imperatively required of all applicants for admission to schools, academies, colleges, charitable institutions, public libraries, art-galleries, and places of labor controlled by incorporated institutions; of all members of conventions, legislatures, political, religious, and deliberative bodies; of every purchaser of a ticket for purposes of travel; and of every voter. In addition, there should be in every district a systematic and periodical inspection of all persons registered in the census by persons qualified and competent to perform compulsory vaccination. This is the scientific treatment of variola.

Respecting the therapeutic management of variola, it must be admitted that there are no remedies known to exert the slightest influence in either cutting short the curriculum of the disorder or in checking its progress in any stage. When vaccination is practised after the disease is fully developed, the two disorders, vaccinia and variola, apparently concur, and proceed pari passu to the evolution peculiar to each. Quinia, the sarracenia purpurea, the salicylate of sodium, emetics, diaphoretics, purgatives, and other remedies and methods vaunted as efficacious, have again and again failed to establish the claims which have been put forth respecting the value of each.

The most important of the considerations to be regarded at the outset of the management of the small-pox patient relate to his hygienic surroundings and nursing—considerations which scarcely differ from those recognized as of general importance in the case of all septic, contagious, and filth-producing diseases.

The timid, the fearful, and the unprotected are to be at once dismissed from the bedside, and trustworthy attendants secured who have received protection by either recent vaccination or a prior attack of the malady. The sick chamber should be sufficiently large and capable of the most thorough ventilation by free access of air. Solar light should be excluded as rigidly and completely as possible, since it is reasonably certain that its access to the face has an etiological relation to the pitting of that part, often the most serious sequel of the affection. It is an interesting fact that pitting is much less frequently noted on those parts of the body from which light is excluded by the covering of the clothing. The temperature of the sick room during the febrile stages of the disorder should not rise above 70° F. nor be permitted to fall below 60° F. Between these extremes a variation may be made in accordance with the sensations of the patient.

During the invasion stage of the disease the patient can rarely assimilate food, but if this be possible it should be given throughout the entire course of the disease in the form of animal broths, eggs, nutritious soups, and milk. Iced and acidulated beverages are often grateful to the palate, and small lumps of ice should be permitted to dissolve slowly in the mouth. Lime-water may be required by unusual gastric irritability. As the disease progresses and the palate and buccal membrane become painful and sore by reason of the localization there of pustular and other lesions, various mouth-washes and gargles may be ordered, such as those containing the chlorate of potassium, the tincture of myrrh, the tincture of cinchona, or even the milder demulcent fluids made by the addition of flaxseed, gum acacia, or powdered elm-bark to water. In almost all such cases the skilled nurse will accomplish a grateful result by frequently cleansing the mouth of the sufferer (especially before the deglutition of aliments) by covering the finger with a soft handkerchief, dipping it in pure hot water, and then thoroughly and gently cleansing the entire buccal cavity. The spray of a saturated solution of boracic acid in rose-water may then be directed over the parts.

Applications of cool and iced water to the skin are commonly grateful, and, as a rule, are accompanied by no danger to the patient, though in the early periods of the disease they unquestionably retard the full evolution of the cutaneous symptoms. For the pain in the back, therefore, which is often the most urgent symptom of the invasion stage of the disease, it is usually preferable to make hot applications. The large rubber bags now in common use, filled with hot water and from time to time applied to the lumbar region, may be employed with good effect simultaneously with iced, spirituous, or camphorated applications to the head.

Numerous indeed have been the topical applications made to the surface of the skin in the pustular stage of the malady, both with a view to assuage the soreness and pain and to obviate the tendency to pitting. The opening of the pustules and the evacuation of their contents (practicable only in other than confluent forms of the disease) has been practised from an early date, but is ineffectual from the standpoint of any practical results thus obtainable. The same may be said of the subsequent cauterization of the floor of the pustular chamber, which only adds to the distress experienced by the sufferer in his skin. Medicated unguents, applied to the skin, containing mercury, iodine, and other substances, are not known to be followed by any better results. It may indeed be laid down as a general rule that fatty applications to pus-producing surfaces where the pathological product is virulent are apt to undergo decomposition and otherwise act unfavorably upon the tissues—a fact first pointed out by Ricord in connection with the treatment of the chancroid. Vaseline, as not liable to undergo chemical decomposition, is not open to this objection.

Curschmann, Kaposi, and other authors are in agreement respecting the value of water-compresses over the surfaces invaded by the eruption—a method of topical treatment which I desire to fully endorse after personal observation of its value. Curschmann recommends compresses dipped in iced, Kaposi those moistened with tepid water. The sensation experienced by the patient will prove the best guide to the temperature of this fluid. I prefer a solution containing one drachm of boracic acid to the pint of water as hot as can be discovered to be productive of comfort, a drachm or two of glycerine being added to the solution. The compresses dipped in this (or a carbolated solution, if the latter is preferred by either physician or patient) should be assiduously moistened and changed regularly by the attendants just as long as they can accomplish good. They operate, first, by protecting the part; second, by keeping it moist; third, by maintaining the surface temperature at the point most pleasant to the patient; fourth, by exercising the gentlest degree of equable compression over the surface. When desired, this may be covered with the Lister protective material or a piece of oiled silk to prevent evaporation at the surface.

In Vienna warm baths, administered either by the process of continuous immersion so generally practised there or by immersion for from two to three hours of each day, have been found to furnish the greatest amount of comfort to the patient. The skin is thus speedily relieved of its tension, the exfoliation of the crusts is hastened, and the time required for the evolution of the cutaneous lesions, if not shortened, is at least not retarded by the accidents of exposure to the desiccating influences of the air—ends which for the patient are practically one. In this country, and especially in private practice outside the larger charities with their ampler provision for these emergencies, nearly the same result may be reached by wrapping the patient completely in sheets wrung out of water of the temperature desired.

From first to last in the treatment of variola, all indications should be made subordinate to that most prominently set forth by the general character of the symptoms—viz. the conservation by every possible means of the vigor of the patient. The tax upon all reserves of vital energy is here so enormous and constant that he will gravely err who for a moment loses sight of this fact. Hence it is that anodynes, chloral, opium and its alkaloids, the bromide of potassium, and similar medicaments, introduced either by the stomach or by hypodermic injection, are to be jealously reserved for emergencies when it would seem cruel to withhold the temporary comfort they may impart. Stimulants are of course to be freely employed whenever they are indicated by exhaustion as this may be shown by a weak pulse and other failing functions of the body, but are certainly best reserved for such emergencies. In general, it may be remarked that the fewer the medicaments ingested by the stomach, and the larger the restriction of the labor of this organ to the task of sustaining the nutrition of the body, the better are the chances of a favorable issue.

It is unnecessary to add that all other indications presented in any given case are to be met, subject to the conditions indicated above. Abscesses are to be opened and antiseptically treated; delirious patients are to be sedulously prevented from doing themselves injury; daily movements of the bowels are to be secured; while the diarrhoea of the typhoid state, occasionally resulting from the exhausted condition of the system when the force of the disease is spent, demands proper control.

Cleanliness is to be enforced by every judicious measure. The skin of the patient is to be washed in tepid water and soap as often as practicable in the course of the disease, and under no circumstances are applications of ointments, washes, or lotions to be allowed to collect in strata upon the surface commingled with the pus and crusts of the disease. At the time of such ablution, and occasionally oftener, the linen and other garments of the patient are to be changed. When the crusts are regularly exfoliating from the surface of the body general warm baths may be ordered, after each of which the surface of the body may be anointed with vaseline or covered with a finely-sifted dusting-powder, such as the corn-starch farina sold by grocers.

Inasmuch as hemorrhagic variola is usually hopeless in character, and remedilessly fatal, Kaposi's liberal use of opiates may be recommended when euthanasia is all that can be expected. So long as there is the narrowest chance of recovery resort may be had to ergot, turpentine and the mineral acids internally, combined with the external use of styptics and ice. But little confidence can, however, be placed in these measures, which will prove entirely ineffective in the great majority of all cases.

In all fatal cases of variola the duties of the physician are not ended by the death of the patient. It is for the benefit of the living that he should require destruction or disinfection and long disuse of all domestic articles that were employed upon or about the patient. The lifeless body should be disposed of by cremation, and medical men should exert their influence in favor of legal enforcement of such a wholesome practice.

VACCINIA.

BY FRANK P. FOSTER, M.D.

SYNONYMS.—Vaccina, Variolæ vaccinæ (Jenner), Cow-pox, Cow-pock, Kine-pox, Kine-pock; Fr. Vaccine; Ger. Kuhpocken, Schutzpocken, Impfpocken, Schutzblattern; It. Vaccina; Sp. Vacuna.

DEFINITION.—An eruptive disease characterized by a cutaneous lesion closely resembling that of small-pox, going through the stages of papulation, vesiculation, pustulation, incrustation, and cicatrization; differing from small-pox in the mildness or almost total absence of the constitutional symptoms, by being communicable only by inoculation, and by the fact that the lesions, as a rule, are developed only at the points of inoculation and in their immediate neighborhood.

This definition holds good for the great majority of cases, but in each of its parts we must take account of exceptions. For example, the lesion does not always follow the regular sequence of changes described. It may stop short at the stage of papulation, constituting the so-called raspberry excrescence, which will be further referred to hereafter; it may pass directly from the stage of vesiculation into that of incrustation, without any such change in its liquid contents as can properly be said to form a pustule; desquamation may take the place of incrustation; and, after an evolution otherwise normal, there may be no formation of a scar, simply because the destructive effect of the lesion has not extended deeper than the epidermis. The constitutional symptoms are sometimes severe, but they are always of very short duration. The disease is said to have been communicated otherwise than by inoculation in the case of some of the lower animals. Thus, Chauveau succeeded in producing some of its phenomena in the horse by causing the virus to be inhaled in the form of spray. It is doubtful, however, if it is possible to eliminate all sources of fallacy in such experiments. Finally, a generalized eruption is occasionally observed, although with great rarity. In stating these exceptions no reference is intended to cases in which complications occur.

NATURE OF THE DISEASE.—Many considerations warrant us in classing cow-pox among the varioliform diseases—chiefly its general resemblance to variola, and the fact that individuals who have been affected by it are thereby more or less fully protected against small-pox. It has been thought, indeed, that cow-pox was in reality but a modified form of small-pox; and this idea has been the basis of one of the theories that have been held as to the origin of vaccinia. Before enumerating and discussing those theories it will be well to mention that cow-pox is spoken of as spontaneous, casual, or inoculated, according to its mode of origin, known or assumed, in individual instances.

Spontaneous or original cow-pox is the name commonly applied to the disease as it is met with in the cow in instances in which its mode of origin is unknown. Strictly interpreted, this expression implies a belief that the affection is capable of being developed in a cow independently of contagion or infection—a notion that seems to be held by many physicians, but not, so far as the writer is aware, by those whose study of the subject has been such as to lend any considerable weight to their opinions. Ordinarily, however, the term spontaneous cow-pox is employed simply as a convenient expression to denote the disease as it occurs naturally in cows, without implying any belief or theory as to its mode of origin.

Casual cow-pox is the term applied in cases that have been contracted by accidental inoculation, whether in the cow or in man. It is manifest that the so-called spontaneous cases are really casual, unless we accept the doctrine that infection is not necessary to the development of the disease.

The term inoculated cow-pox implies that the affection has been produced by intentional inoculation. Here, again, we are confronted with an illogical expression, for a disease that is inoculated accidentally is still inoculated, as much as if it had been conveyed purposely. It may be said, indeed, that the casual disease is due to some other form of infection than inoculation, but for such an assertion there is not a particle of proof.

Passing from this unsatisfactory nomenclature to a consideration of the theories that have been held as to the nature of cow-pox, we are first met with that of its being a disease sui generis, like small-pox, measles, scarlet fever, and the like, and, like them, originating only by its own specific contagion, not being capable of development by a modification of any other contagion, however closely it may thus be counterfeited. This seems the most rational theory of the nature of cow-pox, but it cannot be demonstrated except by disproving all opposing theories; and that has not yet been accomplished.

Another theory is, that cow-pox is really small-pox modified, as the phrase runs, "by passing through the system of the cow." It has been thought possible, indeed, to specify in what way the cow's system could impress such decided changes upon the virulent disease small-pox as to convert it into the mild affection that we know as vaccinia; in other words, it has been imagined that the function of lactation accomplished this remarkable result. This notion may have been due to the observation that so-called spontaneous cow-pox is met with only in cows that are in milk. The significance of this fact, however, is really nothing more than that cows in milk are more exposed to accidental inoculation than other bovine animals—namely, at the hands of the milkers. The fact that in such cases the lesions are almost always confined to the teats and the udder, far from affording any ground for the notion that there is some mysterious connection between cow-pox and the function of lactation, is but another proof that the disease is the result of inoculation. The lesions appear at the points of inoculation, the teats and the udder being the parts handled by the milkers. Moreover, there is no difficulty in inoculating young calves or adult bulls, and the lesions so produced do not vary in a single particular from those observed in so-called spontaneous cases.

Men have been so carried away with this milk theory, however, as even to believe that the virus of small-pox might be shorn of its dangerous properties, so that it would produce only the vaccinal lesion when inoculated simply by mechanical mixture with milk. During the late Civil War one of the Confederate Army surgeons actually put this notion to the test of practice on quite a large scale, inoculating large numbers of persons with a mixture of small-pox virus and milk, terming the practice mitigated inoculation. We can scarcely suppose that he did anything else than variolate these persons, just as he would have done had he used variolous lymph without the addition of milk. His experiments show nothing new; they merely furnish a recent confirmation of the well-known fact, familiar to the old inoculators, that inoculated small-pox is sometimes exceedingly mild in a series of cases.

This theory of the variolous origin of cow-pox, and of the practicability of converting small-pox into cow-pox at will by "passing it through the system of the cow," has taken deep root in the minds of men, especially in Great Britain, where the late Mr. Ceely's experiments and Mr. Badcock's experience seemed to give it some color. Some years ago, however, the question was investigated most practically and thoroughly by a commission appointed for the purpose by one of the medical societies of Lyons, Chauveau being the recorder. Their conclusion was—and their reasoning seems to the present writer incontrovertible—that small-pox and cow-pox were wholly distinct from each other under all circumstances, and that it was impossible to convert the one into the other. But the doctrines of the English investigators, reinforced as they were by the ingenious arguments of the late Dr. Seaton, were not easily to be overturned in their own country or in America; consequently, the practice of variolating cows has been resorted to from time to time for the purpose of obtaining a stock of vaccinal virus of unquestionable authenticity—the so-called variola vaccine. This practice is utterly fallacious, and it is also dangerous, since the disease so produced, however mild it may seem to be, is nothing more nor less than small-pox, with its infectiousness by effluvium and its liability to prove serious even when carefully inoculated.

Quite recently the experimental investigation of the question has been undertaken de novo by a well-known English veterinarian, Mr. Fleming; and, since his conclusions coincide with those of the Lyonnese commission, it is to be hoped that we have seen the last of this rough-and-ready method of improvising a case of genuine cow-pox—a method that, in the light of our present knowledge, can only be characterized as downright malpractice.

The third and last theory we have to consider is that which ascribes the origin of cow-pox to infection from the horse. So far back as Jenner's time it was conjectured that cow-pox was due to the accidental conveyance of the virus of the grease (the eaux-aux-jambes of the French) by reason of the cows being milked by persons who were also employed in the care of horses affected with that disease. Grease is an eruptive disease of horses' heels. Doubtless it has often been confounded with a mere eczematous affection by those who have repeatedly failed in their persistent attempts to inoculate cows with it, and, on the other hand, a localized eruption of horse-pox may have been mistaken for it by those who have supposed themselves to have succeeded in producing cow-pox by inoculating cows with the virus of grease, and have consequently given in their adhesion to the grease theory of the origin of cow-pox. At all events, so far as the writer is aware, that theory is not now held by any well-informed writer.

Still regarding the horse as the originator of cow-pox, we must turn our attention to horse-pox (equinia). Several years ago Depaul of Paris took great pains to establish the fact that horse-pox (an affection totally distinct from grease) was an eruptive febrile disease of horses, an exanthem; that the eruption was generalized, and, being for the most part concealed by the hair, generally overlooked; and that it was capable of being conveyed by inoculation, the lesion being indistinguishable from that of cow-pox. He believed himself to have demonstrated also that it was the contagion of horse-pox that gave rise to cow-pox in the cow.

Depaul's investigations were very keen and his conclusions were exceedingly plausible, but they cannot be called convincing, notwithstanding the fact that Constantin Paul succeeded for a time in popularizing a stock of horse-pox virus as material for vaccination. At about the same time the Beaugency case of cow-pox was discovered, and the perfectly satisfactory use that has been made of that stock may have thrown Depaul's theories and Paul's practice undeservedly into the background.

We can only say, in summing up, that the small-pox theory is utterly untenable, that the horse-pox theory has not been disproved, and that the theory that regards cow-pox as derived neither from small-pox nor from horse-pox, but as a disease sui generis, although not proved, is the most rational of all, and the most in keeping with known facts.

ETIOLOGY.—Nearly everything that could be said under this head has already been considered. It may be added that meteorological conditions have been supposed to favor the prevalence of the disease among cows. More precise observations are needed to enable us to determine whether or not there is any truth in this supposition. It has been said that the affection is most apt to prevail during warm and moist seasons. This is contrary to what we might have imagined, as warmth and moisture are quite destructive of the vaccinal virus. Under ordinary circumstances, however, the contagium often proves wonderfully tenacious of life, and the disease, once introduced among a herd of cows, is prone to linger for months, or even years, attacking animals recently added to the stock and young cows during their first lactation. As has already been stated, age, sex, and parturition can be regarded as etiological factors only in so far as they favor the occurrence of accidental inoculation. In the human subject vaccinia occurs generally as the result of intentional inoculation, as will be more fully referred to when we come to the consideration of vaccination. Insusceptibility is occasionally met with, both in the cow and in man, but it is very rare. Perhaps it may be explained in some instances by the subject having really had the disease, or indeed small-pox, either before or after birth, in so mild a form as not to have left the characteristic marks. Certain it is that the lesion does not always leave a permanent scar, especially in the cow.

GENERAL COURSE OF THE DISEASE.—This is best studied in cases that have followed intentional inoculation, for here we know the chronological sequence of events. Depending somewhat upon the method of inoculation, and perhaps also to some extent upon the state of the skin at the site of the inoculation, or even upon a systemic condition (since some vaccinators hail it as a harbinger of success), at the time of the operation a ring-like erythema may be seen surrounding the inoculation. This is exceedingly evanescent, being doubtless due to vaso-motor action, and is not often witnessed.

Ordinarily, no effect whatever is observed until after the lapse of two or three days, when a red papule is formed. This papule increases in superficial area, but not in height, and gradually loses its redness. It assumes a circular form, or, in the case of a compound pock (for that is the proper name for the lesion), a configuration representing segments of several circles, and as it increases in area it becomes more and more raised at the border (the bourrelet of French writers), while the central portion, which also increases in size pari passu with the peripheral annular vesicle, does not become more elevated, but remains depressed, giving the pock as a whole the peculiar shape termed umbilication. Up to the eighth or tenth day, inclusive, the marginal elevation contains a limpid fluid termed lymph, and consequently presents a pearl-like lustre. At this period a rather sudden increase takes place in the corpuscular elements contained in the lymph, causing that liquid to become thick and opaque, so that the elevated margin of the pock, which before had shown the pearl-like lustre alluded to, now comes to look as if made of tallow.

At the same time what is known as the areola forms around the pock, and constitutional symptoms show themselves. The areola is a circumscribed redness of the skin, perfectly circular in form and of five or six times the diameter of the pock itself. It is sharply defined and of a vivid red hue. Usually it is a mere hyperæmia of the skin, but in some instances, especially where the process of pock-formation is decidedly pronounced, a few papillary elevations are to be seen in the immediate neighborhood of the pock, and at that situation there may also be some lividity. After a few hours' persistence in the form of a disc the areola begins to disappear, the redness fading first at the central portion, so that in its declining stage it assumes the shape of a ring which constantly grows narrower and narrower at the expense of its inner portion, and finally disappears altogether. In the cow the areola is only a faint line immediately around the pock.

Constitutional symptoms are invariably present in cases that follow the regular course. The temperature rises one or two degrees Fahrenheit, the appetite becomes impaired, and sleep is somewhat disturbed. In many cases, mostly those of secondary inoculation, the symptoms are more severe; the fever runs higher, and may be accompanied with transient delirium; nausea is experienced, perhaps with actual vomiting; and severe pain is felt in the head and along the spine, the latter being most marked in the cervical region. These symptoms usually last but a few hours, and they are apt to be accompanied by a modification of the areola whereby it loses its disc-like outline and becomes diffused irregularly, especially, if, as is usual, the inoculation has been done on the arm, in a downward direction toward the elbow.

Along with these phenomena intense itching is often felt at the situation of the pock, being an aggravation of the pruritus that in a mild form accompanies the greater part of the whole course of the lesion. Supposing the arm to have been inoculated, the lymphatic glands of the axilla now become swollen and tender, but their suppuration is unusual, and is to be regarded as a complication.

To go back to the pock: some time before the contents of the marginal elevation become opaque the central portion is converted into a crust of a brownish color, and finally, from the tenth to the fifteenth day, the bourrelet itself, having ceased to increase in size, takes part in the process of incrustation, the completed crust representing the form of the pock, having a circular ridge at the border, at which part its color is not so deep as at the centre. The crust usually falls off between the fifteenth and the thirty-fifth day. It is hard, translucent, and of a prune-juice color; thick at the centre and thin at the periphery; smooth on its attached surface and somewhat wrinkled on its outer aspect; surmounted at the centre by the epidermal débris produced by the operation of inoculation, mingled perhaps with more or less dried blood.

After the crust falls off a reddened surface is left of a cicatricial nature, usually somewhat depressed below the level of the surrounding skin, and frequently showing lesser pits, which latter appearance is termed foveolation. Instead of these pits, radiated striæ are frequently left. Gradually the scar loses its red color, and, like other scars, finally becomes paler than the surrounding skin. It is usually permanent.

IRREGULARITIES IN THE COURSE OF THE DISEASE.—Ever since cow-pox first became the subject of medical study deviations from its typical course have been noticed, and have been the theme of a good deal of speculation. The older writers, indeed, bestowed no little attention upon what they considered to be not irregular forms of vaccinia, but distinct affections with which it was liable to be confounded. Their descriptions of these diseases, which they termed spurious cow-pox, are, however, so vague as to possess but little more than an historical interest. In regard to affections met with casually in the cow, we can often determine their nature only by test-inoculations, and even that criterion is not always thoroughly convincing; for, on one account or another, we may fail in the attempt to propagate true cow-pox, and on the other hand, if we admit that there is a radical difference between cow-pox and small-pox, it is manifest, bearing in mind the errors into which experienced investigators have fallen, that we may propagate small-pox through a long series of experiments without once suspecting it to be anything but cow-pox. We may, nevertheless, always determine, provided we succeed at all, whether we are dealing with a disease that protects against vaccinal and variolous inoculation.

In the human subject we seldom meet with affections that counterfeit vaccinia, although, if we take only the lesion into consideration, there are certain contagious forms of herpes that may give rise to doubt, and possibly the same may be true of impetigo contagiosa.

Turning, then, to the irregularities properly so called, we have first to consider the absence of constitutional infection. This must not be confounded with the mere lack of obvious constitutional symptoms; what is meant by the expression is, that in certain instances the local lesion may appear typical, and yet no such impression be made upon the system as to render it proof against subsequent inoculation. Early in the century the possibility of this lack of systemic infection was insisted upon by Mr. Bryce of Edinburgh, who invoked it as an explanation of the occasional failure of vaccinia to protect against small-pox. The practical question was, how to decide, in a given instance, whether general infection had or had not taken place. In the opinion of many observers—and that notion has cropped out every now and then up to the present day—absence of the areola furnished at least presumptive evidence that the constitution had eluded infection. But, whatever may be held theoretically, it must be conceded either that the general system very rarely fails to feel the impress of the disease, or else that the criterion is fallacious. For in an experience of seventeen years the present writer has not known of a single instance in which a vaccinal lesion that pursued a regular course in other respects has failed to be accompanied by the areola. And certainly Mr. Bryce himself must have attached little if any importance to it, for he took great pains to establish a means of determining the presence or absence of constitutional infection—the so-called Bryce's test. This consists in repeating the inoculation at a certain period in the evolution of the disease, the theory being that systemic infection does not take place at once, but only after the lapse of a number of days from the time of the inoculation. Up to that time a repetition of the inoculation is possible, and, if systemic infection results from the first one, both lesions will mature at the same time, the second one following an accelerated course, reaching its acme rapidly, although dwarfed in size. If, on the other hand, the first inoculation failed to infect the constitution, the second one will pursue its course in the usual manner. Moreover, at a certain time, generally about the fifth day, a repetition of the inoculation will fail altogether if the original insertion has really infected the system. The present writer can testify that Mr. Bryce's statements are correct; he has applied the test in many cases, but in no instance has he been led to the conclusion that constitutional infection had failed to take place. He is inclined to think, therefore, that such failure is exceedingly rare.

Passing over the multiplicity of irregularities in the lesion that were described by the older observers, it seems that there are a few that are of practical importance. In the first place, there is a variety of pock to which it is not easy to give a definite name, but which is characterized by a lack of decided elevation above the surrounding skin (a deficiency for which it makes up in superficial area), by the early formation of a thin, flimsy, straw-colored crust, and by the utter failure of the characteristic firm brown crust of the typical variety to become developed. This form of irregular pock has not been seen by the writer of late years, but before animal vaccination came into general use he met with it frequently, mostly in cachectic children. Notwithstanding its sprawly, unsatisfactory appearance, it is undoubtedly genuine, for the typical lesion may be produced by inoculation with its contents.

Another irregularity of the pock is what is familiarly termed the raspberry excrescence. A red elevation forms at the seat of inoculation, and at first promises to follow the typical course, although it may be tardy in making it appearance; but it never advances to full development. It becomes indolent, and may last for several weeks, or even months, in the form of a hard, flat nodule of a bright-red color, not unlike a small nævus. In many instances it has a succulent look, but no lymph can be obtained on puncturing it. No areola appears at any time, and finally the lesion slowly disappears, leaving no trace of its existence. It is probably an abortive form of pock, in which only the papillary layer of the skin takes part, without any exudation into the epidermis. It is seldom, if ever, protective against small-pox, for it constitutes no bar to a subsequent vaccination. This irregular pock has been observed from time to time ever since the early days of vaccination, but for the past six years it has been seen more frequently in New York than for many years before. Now, however, it seems to be growing less common. The writer is not aware of any satisfactory explanation of its occurrence. It is seen in all sorts of subjects, and seems to follow the use of one variety of virus as much as the employment of any other.

What has been termed generalized vaccinia is another form of irregularity. The expression is a vague one, covering as it does not only the very rare cases of true eruptive vaccinia, in which a general eruption of pocks takes place as a consequence of constitutional infection, playing the part of an exanthem, but in addition those instances, not very uncommon, in which pocks are formed here and there on the body, probably as the result of the accidental transfer of the virus from the pock by scratching. Under such favorable conditions—the immediate transfer of lymph from a pock in which the specific evolution is going on vigorously—the slightest penetration of the epidermis with the nails is enough to secure self-inoculation. In view of this facility with which it may be effected, we should be very careful not to jump hastily to the conclusion that in any given case of generalized vaccinia the supplementary pocks are truly eruptive; as a matter of fact, the present writer has never seen an instance in which he was convinced that such was the case. Where the pocks are very numerous, especially in subjects with an irritable skin, much distress may be caused by the itching and by the consequences of scratching, and marked febrile reaction may accompany the process; so that, in view of the great similarity of the lesions to those of the variolous eruption, much doubt is sometimes entertained as to whether the disease is not really small-pox. This question cannot always be definitely settled at first, but the failure of the secondary fever of small-pox, together with the fact that the disease does not spread by infection, will generally suffice to decide it.