Chapter III · ASEPSIS AND ANTISEPSIS

To understand thoroughly and rationally to practise asepsis and antisepsis, it is necessary for the operator to realize the difference between the two terms. There is a general belief among the laity—and, unfortunately, among some chiropodists—that these two words are synonymous, and that asepsis and antisepsis comprehend the same system of treatment. This is a fallacy.

Asepsis is a condition in which living pyogenic organisms are absent. Aseptic surgery comprehends the performance of an operation in a field free from pyogenic or septic germs, with sterilized hands, instruments, etc., preventing the introduction of germs from without.

Antisepsis is the process whereby germs causing disease, fermentation, or putrefaction are destroyed. Antiseptic treatment comprehends the use of certain drugs or a group of drugs which prevent the action of germs, which inhibit their growth, or which destroy them.

In the comparison of these two foregoing definitions the distinction between the two words is clearly brought out. We speak of a drug—mercuric chloride, for instance, as having an antiseptic action. We speak of a piece of sterile gauze—sterilized, we will say, by heat—as being aseptic. The mercuric chloride is an active substance which, applied to a septic area, will proceed energetically to its work of germ inhibition or destruction. The sterile gauze, placed over a similar area, has no power to prevent or even retard the action of the invading bacteria, let alone destroy them, but once having been rendered free from such germ life by an antiseptic, the aseptic gauze will keep the area in a germ free condition for a greater or lesser length of time.

To sum up, then, the term “antiseptic” is applied to a drug or group of drugs from whose actions bacteria are rendered innocuous or are destroyed; and “aseptic” is applied to a condition in which no germ life exists, having previously been freed from such contamination by the use of an antiseptic agent.

Some years ago the term “germicide” was used in contradistinction to that of “antiseptic.” This usage was brought about through the belief that some antiseptics would not destroy all forms of germ life. Germicide, at that time, was used to distinguish a drug which would energetically attack and destroy all bacteria. Inasmuch as, on close survey, it was found that the antiseptics which would not destroy all germs were, in a great measure, weaker solutions, and that, if used in greater strength, they would be efficient as purifying agents, this distinction, today, has been done away with, and the terms germicide and antiseptic are used synonymously and will be similarly employed in this chapter.

ANTISEPSIS

Antiseptics to be actually efficient must be brought in direct contact with the septic area. There is an erroneous belief that all of the official germicidal agents and a majority of the proprietary preparations, the advertising matter of which latter claims for them great antiseptic proprieties, are efficient in deep-seated, septic processes by mere surface application. This is wrong, and it is for this reason that in all septic inflammations, free drainage must be obtained and maintained, and the actual surface upon which the bacterial action is in evidence must be exposed before the beneficial action of antiseptic agents can be exerted or prove beneficial.

The skin unquestionably does, at times, absorb a drug applied to its surfaces; but where an active infective process is present, the antiseptic action of a germicidal agent is practically nil unless the drug is brought into direct contact with the septic surface.

The present success of Dakin’s solution, for instance, is not so much on account of the great efficacy of the solution itself—although it has potent germicidal properties—as it is due to the Carrel method of irrigation whereby this solution is carried to the most obscure recesses in which the infective process is present. Applied superficially, as must needs be done in chiropodial practice, we find that Dakin’s solution is of no greater value than many other antiseptic agents, except perhaps that, on account of its being non-toxic, it can be used in cases where germicides with strong toxic properties are contra-indicated.

HISTORY OF ANTISEPTICS

The story of antiseptics is one of the most interesting in all the pages of medicine and surgery.

Antiseptics were employed as remedial agents long before the exact causes of putrefaction or fermentation were known. The Egyptians preserved the human body against the attacks of putrefactive organisms, without any knowledge of the character of the organisms causing decay. The wonderful state of preservation in which we, today, find the bodies of their kings, was brought about by means of balsams containing, probably, such antiseptics as benzoic and cinnamic acids.

In the sixteenth century the surgeons treated gunshot wounds with boiling oil. They knew that if these wounds were left untreated, putrefaction would ensue accompanied by great suffering, and the ultimate death of the patient. They also knew, empirically, to be sure, that boiling oil applied to the wound prevented the development of this putrefactive process, but they did not know why such was the case, nor did they realize that, by this use of superheated oil they were merely cauterizing the wound.

Ambrose Pare (1510-1590), who started life as an apprentice barber-surgeon in Paris, became a military surgeon in the army of Francis I, in Piedmont; and he, more from a humane feeling, as his writings tell us, than from any particular scientific knowledge, had the temerity to dispense with this oil boiling technic and to trust to a simple bandage saturated with a concoction of herbs. Pare, however, has no particular place in the development of antisepsis, his principal contribution to surgery being in the development of the use of the ligature for large arteries, which made amputation on a large scale possible for the first time.

Antiseptic surgery dates from the last few years of the nineteenth century, and among the names of its sponsors which will ever remain foremost, are Pasteur and Lister.

Lister’s use of local antiseptics in surgery, however, should not, perhaps, be spoken of as a discovery. Without detracting in any way from the credit due him, it should be referred to, more correctly, as a practical application, in particular of the theories of Pasteur, and of several previous investigators.

Prior to Lister’s use of phenol, the substance had already been described by Reichenbach in 1832, and by Runge in 1834, as one which would prevent putrefaction. Long before these, tar and a number of similar products were advocated and used for foul ulcers, but the fact remains that Joseph Lister placed the use of antisepsis in connection with surgical procedures on a sound and practical basis.

Taking as a working basis the experimental researches of Louis Pasteur (Communications on the Theory of Fermentation 1853, 1858; The Germ Theory, read before the French Academy of Sciences on April 29th, 1878, and The Extension of the Germ Theory, which appeared in 1880), Joseph Lister, an English surgeon, developed his theory of antiseptic wound treatment. His first experiments were made public in 1860. At that time he stated that the evils observed in open wounds were due to the admission into them of organisms which “exist in the air, in water, on instruments, on sponges, and on the hands of the surgeon or the skin of the patient.” Having accepted the germ theory of putrefaction, Lister applied himself to discover the best way of preventing harmful organisms from reaching the wound from the moment it was made until it was healed, or, if this could not be done, of using some agent to destroy the organism, either before it reached the wound or after it had lodged there.

Acting on the advice of Lemaire, who had already experimented with several substances which were known to be antagonistic to putrefaction, Lister chose carbolic acid, which he used first in the crude form.

His experiments extended over a number of years during which period he surmounted many obstacles, until in the early 80’s he finally perfected his antiseptic treatment of wounds by means of carbolized sprays for the air of the room, carbolized solutions for irrigation, for instruments and for surgeons’ hands, and carbolized dressings with mackintosh protection, as post-operative procedures. Today we smile at the idea of a dressing of phenol in any strength, covered with mackintosh protection; but in advocating this procedure, Lister had in mind, as nearly as possible, to cover the wound so that no external agencies might come in contact with it.

From this beginning, our present day antiseptic surgical technic has been gradually developed. Mercuric chloride gradually replaced phenol, and the use of the carbolic spray was discontinued on account of its chilling influences on exposed surfaces, which tended to lower their vitality.

Aseptic surgery owes its origin primarily to antiseptic surgery. Not long after Lister’s rules for antiseptic procedure were generally observed, the realization came to many that the success of Listerian surgery did not depend so much upon the spray or the carbolized gauge, as it did upon cleanliness; the surgeon’s hands, the instruments, the area to be operated upon, and the dressings must be clean—surgically clean.

Today we have the rule of “the soap and nail brush,” the sterilized instruments, the aseptic rubber gloves for the operator’s hands, and the sterile dressing. The modern surgeon uses no antiseptics during operations; he uses instruments which are positively germless and the dressings of aseptic gauze are not impregnated with medications.

ANTISEPTICS

The important subject of antisepsis embraces such a variety of agents which may be employed in the numberless conditions arising, that it is usually divided into three groups. (1) general antiseptics; (2) local antiseptics; (3) internal antiseptics. For the purposes of the podiatrist, some knowledge of the first group is desirable, but his principal thought on this subject should be given to a thorough knowledge and understanding of the second group, those for local application. Inasmuch as the podiatrist is not allowed to prescribe internal medicines, no discussion of the third group, comprising internal antiseptics, will be included in this chapter.

General Antiseptics, or disinfectants, play so great a part today in preventive medicine that the podiatrist should at least inform himself on the general principles involved.

Under this group we find a number of agents which are employed for purposes of general disinfection. First on the list comes:

Sunlight. The bright, direct rays of the sun, coming into direct or immediate contact with germ life, are the best of all disinfectants. This does not mean their merely shining on one side of a carpet, or on small masses of blood, pus or sputum, but their penetrating each individual microorganism. When this can be accomplished, all germ life is destroyed in a few hours. But this cannot be accomplished in all conditions, and, unless the penetration of sunlight is thorough it is not dependable. For this reason we are forced to rely on other agents (thermal and chemical) to accomplish our purpose.

Heat. A direct flame will, of course, instantly destroy all forms of microscopic life; dry air heated to 160° C. (320°F.) will destroy all disease germs—but not all spores—in one hour. Moist heat, water or air saturated with aqueous vapor, heated to 75°C. (167°F.) will destroy most germs.

Boiling water will even kill spores in ten minutes, if they are not in small masses. To break up such masses the addition of a small amount of baking soda will serve, not alone to dissolve these albuminous collections, but will also keep instruments from rusting (see Sterilization). Steam, or air which is supersaturated with steam, is fatal to pathogenic organisms, and at a much lower temperature than dry hot air.

Chemicals which may be included under this group of general disinfectants are: formaldehyde, lime, sublimed sulphur and chlorinated lime.

Formaldehyde, formalin or formic aldehyde, is widely used as a general disinfectant. It is exceedingly powerful, one part of the gas rendering fifty thousand parts of air irrespirable. The action of formaldehyde is increased by moist heat, it does not actively corrode metallic instruments nor does it injure fabrics. The formaldehyde cabinet is used generally by podiatrists. (See Sterilization).

The official preparation of formaldehyde is a 37% solution known as liquor formaldehydi, U. S. P. For the disinfection of rooms, the solution may be applied directly by washing or spraying, or it may be used in vapor form. When the latter is employed, the windows and doors are tightly closed and all the crevices are plugged with paper.

Lime, calx, or calcium oxide, is extensively used but must be freshly prepared to be effective. Unslacked lime is a cheap, and an efficient means of destroying animal matter, but the milk of lime, freshly slaked, is by far the most desirable form.

Sublimed Sulphur, or flowers of sulphur, is not so generally used today as is formaldehyde. It should be used only in places where nothing can be injured by the corrosive action of the resulting sulphurous acid. As with formaldehyde disinfection, the vapor must come into actual contact with the microorganisms and the atmosphere should be moist.

Chlorinated Lime, improperly called chloride of lime, is a ready source of chlorine, and is a convenient and inexpensive agent for general disinfection purposes. It has a corrosive action, however, and therefore should not be used in places where this action will do damage.

There are a number of drugs which may be more or less successfully employed as general antiseptics and disinfectants. Phenol, cresol, potassium permanganate, mercuric chloride and copper sulphate are on this list, but as the podiatrist is principally concerned with the second group, local antiseptics, these drugs, which are included usually under that group, will now be discussed.

It is deemed wise before passing on to the subject of local antiseptics, to bring one important point to the attention of the student. Under no circumstances must the term deodorant be confused with disinfectant. A deodorant is an agent which merely destroys or conceals an offensive odor and has no power whatsoever to actually destroy or inhibit the growth or action of bacteria. Many disinfectants are also deodorants, but a deodorant may not always have germicidal properties.

Local Antiseptics are agents which are applied locally and externally for the purpose of arresting putrefaction. In podiatry there are a number of drugs belonging to this class which may be safely employed and whose beneficent action may be depended upon.

There has been a marked tendency in podiatry in the past toward the use of a number of proprietary drugs for germicidal purposes. Happily this practice is dying out, and a few years will find the therapeutics of podiatry established on a sound, rational basis.

The following local antiseptics can be safely employed in podiatry operations:

Alcohol is used generally in practice to render fields of operation surgically clean. The pure grain alcohol is used for the immersion of instruments prior to operation, but a 60% solution is found more efficient for antiseptic action upon the body surfaces. A pledget of sterile cotton, saturated with alcohol and placed over a part, insures absolute asepsis in a short time. Alcohol alone cannot be practically used as a wet dressing. In this connection it is combined with boric acid, equal parts, and is efficient as an antiseptic.

Liquor Alumini Acetatis, an 8% aqueous solution of acetate of aluminum, is used almost entirely as a wet dressing in infective inflammations. It is non-toxic and, while it is irritant to extensive denuded surfaces, it is usually employed for its astringent action.

Balsam of Peru is used chiefly in podiatry as a stimulating agent; its antiseptic properties, however, are well known and are probably due to the benzoic and cinnamic acid which it contains. It is used either alone, in ointment form, 3% to 10%, or in combination with collodion, 10%.

Boric Acid is employed principally as a wet dressing in cases of inflammations. It is quite free from toxicity and is but slowly absorbed. It is also used in powder form as an antiseptic.

Boroglycerine, U. S. P., contains 30% of boric acid. It is found particularly effective in the treatment of indolent ulcers where a mild antiseptic lotion is desired.

Borate of Sodium (Sodii boras, U. S. P.), borax, has an alkaline reaction and for this reason is sometimes substituted for boric acid. It is soluble in 16 parts of water.

Dakin’s Solution is a solution of hypochlorite of soda, ¹⁄₂%. The preparation of the original solution is so difficult that large quantities of the drug are not easily obtainable. Chlorazene, an American product which is recommended by both Dakin and Carrel, is obtainable in tablet and in ointment form. One tablet dissolved in 8 ounces of water makes a solution, ¹⁄₂ of 1%. The solution is unstable, necessitating its being constantly made fresh, and for this reason the use of the drug is not practical in podiatry practice today. When used, the solution must be changed within twenty-four hours; if this is not done it becomes irritant, setting up an acute dermatitis. The drug is used as a wet dressing, but never with rubber or oiled silk covering.

Di-Chloramin-T, the newer form in which Dakin’s solution is used, is a 5% or 10% hypochlorite of soda solution in oil of eucalyptus. This combination is found to be less irritating than the original solution. It is used as an antiseptic dressing.

Glycerinum, U. S. P., is not alone useful as a mild antiseptic but is also extensively used as a vehicle for many other substances in the treatment of skin lesions.

Hydrogen Dioxide, peroxide of hydrogen, is used principally in podiatry to decompose pus in which bacteria are protected from the action of other antiseptics. As the antiseptic action of hydrogen dioxide is dependent solely upon the liberation of its component oxygen, it is easily seen that once the ebullition occurring on its contact with albuminous surfaces ceases, it becomes inert. “Peroxide” is used as a pus germ destroying agent, and to loosen dressings which have become adherent from copious discharge.

Iodine, Tinct. Iodii, U. S. P., is 7% of iodine in alcohol, and presents the best agent known at the present time by which surface sterilization can be obtained. It is highly germicidal, but continued applications are decidedly corrosive and not alone inhibit the development of new granules, but also cause severe dermatitis, and at times symptoms of iodine poisoning. The one feature which prevents its use in some chiropodial procedures is the discoloration of the tissues produced by its application. It may be used full strength or diluted with water, as weak as a 1% solution.

Iodoform, despite its unpleasant and suggestive odor, is an efficient antiseptic and is used in powder form. Its antiseptic action is principally derived by the slow liberation of its component iodine.

Several forms of mercury are used in podiatry.

Bichloride of Mercury, or mercuric chloride, is used, ¹⁄₂₀₀₀, to prepare fields for operation, and from ¹⁄₅₀₀₀ to ¹⁄₁₀₀₀₀ as a wet dressing in infective inflammations. It is highly toxic and should never be used for any great length of time, or on a denuded surface of any size, as it is rapidly absorbed into the general system, and its corrosive action tends to inhibit the development of new granules. There are also systemic effects to be feared from its absorption.

Mercurous Chloride, calomel, can be used as an antiseptic dusting powder on many chiropodical lesions. It is combined generally with bismuth, equal parts, as an antiseptic and astringent application for blisters and burns.

Unguentum Hydrargyri, U. S. P., is a 50% ointment, used principally in chiropody in the treatment of parasitic diseases of the nails.

Unguentum Hydrargyri Ammoniatum, 10%, is an antiseptic ointment used safely in any case where such action is desired.

Phenol Liquefactum, U. S. P., carbolic acid, is used as an antiseptic in solution, 2¹⁄₂%. It is highly toxic and is never used as a wet dressing under any circumstances. Phenol, besides its toxic properties, has an anesthetic action on the peripheral nerves, and due to this action, many cases of carbolic gangrene have been reported.

Liquor Cresolis Compositas, U. S. P., also a coal tar product, can be advantageously used in a general spray for the foot, or for the special field of operation. It is antiseptic, and its saponaceous properties (it is a solution of cresol and soap) aid in softening the tissues as well as in cleansing them. It is used in 2% strength.

Lysol, an unofficial phenol derivative, is also used as a general spray, 2%, in water. Its odor is very strong and it is therefore objectionable to many persons.

Thymol is a phenol occurring in a volatile oil. It possesses strong antiseptic properties, but its comparative insolubility in water has prevented its more general use. The only official combination of thymol is

Thermolis Iodidum, U. S. P. Thymol iodide, or more correctly dithymoldiiodid, has been better known for years under its trade name “aristol.” It is used as a dusting powder, is actively antiseptic by the liberation of iodine, and has become popular as an iodoform substitute.

Potassium Permanganate, U. S. P., has its greatest usefulness as a local antiseptic application where deodorant action is also desired. In the treatment of indolent, foul ulcerations it is very efficacious.

Sulphur is used principally in podiatry in the form of Unguentum Sulphuris, U. S. P. It is composed of 15% of washed sulphur, usually in a lanolin base, and has a mildly stimulating and antiseptic action.

There are any number of additional drugs, both official and unofficial, which can be and are used in podiatry practice, but it is deemed sufficient to name the foregoing which constitute a complete armamentarium for all antiseptic procedures.

THE FIELD OF OPERATION

For rendering the field of operation aseptic the following technic will be found efficient:

In addition to preparing the immediate field it is found advantageous to treat the surrounding areas to prevent the washing in of bacteria. To accomplish this the use of an antiseptic spray is to be advocated.

Equipped as the podiatrist is with modern air compressing devices, this is a simple matter, the principal question being the selection of a proper spray.

An aqueous solution of alcohol is exceptionably suited for purposes of this kind and where a lesion is already present this drug should be used to the exclusion of all others.

Most cases the podiatrist is called upon to treat, however, present no lesion, yet asepsis must be procured in the event of a lesion being made during his operative procedures. In cases of this nature a spray of liq. cresolis compositus, U. S. P., 2¹⁄₂%, will be found to be an agreeable and efficient application. This solution has but a slightly disagreeable odor and has marked softening as well as antiseptic properties.

After the whole foot has been thoroughly sprayed and dried with a sterile towel, the immediate field of operation may be coated with tr. iodine, 3¹⁄₂%. This is one-half the strength of the official tincture and is advocated to obviate the deep stain occasioned by the use of the 7% tincture. In many cases, however, no stain whatsoever can be countenanced for fear of obliterating some diagnostic point, and it may be found advisable to dispense entirely with iodine, substituting alcohol, 60%, in its stead.

A pledget of sterile cotton saturated in this solution of alcohol and placed over the area under treatment, will produce asepsis in a short time. The penetrating qualities of alcohol are, however, found to be increased, if application is made by means of a cotton wound applicator, the mixture being rubbed vigorously into the parts.

The use of either of these two methods will procure a sterile field upon which any chiropodial operation may be commenced and completed in safety.

Should hemorrhage be caused during operation, it may be arrested in a number of ways: (1) Bichloride of mercury, ¹⁄₁₀₀₀, may be applied on a pledget of sterile cotton. This will serve to check the blood flow by hastening coagulation, and at the same time will procure asepsis. (2) Tr. iodine may be painted over the lesion and digital or tourniquet pressure applied until coagulation is complete. (3) Astringent and antiseptic dusting powders may be applied. (4) Styptics (Monsel’s solution is efficient and the least irritating) may be used, but it must be remembered that these drugs combine no antiseptic qualities and therefore it is good surgery to apply tr. iodine before their use.

A hemorrhage arrested by any of the foregoing methods should be dressed antiseptically, as well. For this form of dressing, antiseptic ointments or dusting powders are found to be most effective.

ASEPSIS

The topic of asepsis will be found more thoroughly, discussed under the chapter “Sterilization.”

Aseptic procedure comprehends the employment of all instruments and materials which have by some means been previously rendered free from germ life. Instruments are to be thoroughly sterilized by boiling in water for at least fifteen minutes, the hands of the operator are to be thoroughly cleansed, or are made as nearly germ free as is possible; the dressings used are to be surgically cleansed (usually by moist or dry heat) before application; and no antiseptic solutions are included in the treatment.

It is doubtful if aseptic procedures can be practised in podiatry to the exclusion of antisepsis. It must be remembered that after most chiropodical surgical procedures, the foot surfaces (again encased in a shoe) teem with septic matter which present the mediums best suited for the propagation of bacterial life,—heat, moisture and darkness.

An aseptic dressing having been employed, the length of time it will remain germ free is problematic; so it is found advisable in most instances where there is danger of infection, to resort to an antiseptic method of treatment rather than to rely solely upon the aseptic.

Dr. Edward Adams, Professor of Surgery at The First Institute of Podiatry, lecturing to the students on “The Newer Antiseptics in the War,” spoke as follows:

“The immense number and variety of wounds encountered in the present war, necessitating the care of many thousands of men at one time, and the entirely new situations created by modern warfare, have led to an amount of research heretofore unknown. True to its traditions, the medical profession has endeavored to discover the best methods in treatment and to render the best service in its power to bestow. Never has the surgeon had to face greater difficulties and never has he recorded more brilliant success.

“Where practically every wound is infected, antisepsis has necessarily received unusual attention, and the merits of different substances having antiseptic properties have been thoroughly discussed and have narrowed down to a very few. The fact is emphasized that those which are strong enough to be antiseptic must be used with great care, especially in cases where drainage is not free.

“After many trials and many discussions the tendency of men of the greatest experience, however, is to reduce the problem to very simple terms which may be expressed thus: (1) How to secure a clean wound. (2) How to give nature a chance with a minimum of interference, since, after all, she must do the healing.

“The early part of the war demonstrated the fact that both antisepsis and asepsis, as heretofore practised, have been vanquished by Mars. By some it was even considered that Lister’s work went for naught. Now, however, antisepsis and asepsis, each in its proper place, have come into their own again and Lister is still the apostle of good tidings.

“The reasons are plain: first, at the beginning of the war we did not possess sufficiently effective antiseptics such as have now been given us; second, we were not masters of an efficient technic. We owe these innovations especially to two men, Dakin and Carrel, who have wrought a marvelous change. Lister taught us above all how to prevent infection; Dakin and Carrel, following his principles, have taught us how to conquer even the most virulent infections. For nearly half a century surgeons have been fighting strenuously against infection, but it required the stimulus of war to enable us to win a victory. Prevention and cure both are ours now.

“The newer antiseptics that have been discovered and used since the war are chiefly: Dakin’s solution of hypochlorite of soda, di-chloramin-T, eusol and eupad, both preparations of hypochlorous acid, flavin, acriflavin, and proflavin, and a mercurial preparation known as mercurophen.

“These newer antiseptics, especially the flavin group, have pronounced bactericidal qualities, but it is too recent as yet for them to have been tested on a sufficiently large scale to permit of positive conclusions as to their value. Flavin is described in detail as to its process of manufacture and its action in an article by C. H. Browning and his colleagues in the Bland-Sutton Institute of Pathology of Middlesex, London (British Medical Journal, January 20, 1917, page 73). For technical reasons flavin as one of the acridin group is now called acriflavin, and a more potent preparation is called proflavin, which is described in the British Medical Journal, June 9, 1917. Dakin, in the same journal, June 23, 1917, endorses Browning’s method of treatment with acriflavin. Its antiseptic action, instead of being diminished by blood serum, is increased thereby, even up to five times its potency. Moreover, as used by Browning, it is harmless to the tissues and does not interfere with the activity of the leucocytes nor with phagocytosis.

“The most important paper yet published on these newer antiseptics is by Browning Culbranson and L. H. D. Thornton in the British Medical Journal, July 21, 1917. The principal points brought out by their experiments with the use of acriflavin and proflavin are as follows: first, that the bactericidal power of acriflavin and proflavin, instead of being diminished and even destroyed by the contact of blood serum (as is the case with hypochlorite of soda, bichloride of mercury, etc.), is greatly increased from 10 to 40 fold. Second, as a result, these two antiseptics, though acting at first merely by inhibiting bacterial growth, later become increasingly powerful and actively destroy the bacteria. After two hours’ contact in the presence of serum, mercuric chloride is practically equal to acriflavin in its lethal effect on the streptococcus and bacillus coli, but by this time the effective action of the mercury salt on the bacteria has come to an end, and a concentration which has then failed to kill the organisms, exerts little or no inhibiting effect on the proliferation of the survivors. On the other hand, concentrations of the flavins, which at this period have merely inhibited multiplication, later on prove bactericidal, so that finally the flavin compound is ten to twenty times more lethal than corrosive sublimate. Therefore, instead of renewing the solution every two hours, only one or two daily dressings are required. Moreover, they are apparently harmless to the tissues. Experiments show that such concentrations of flavin as will effectively control the bacteria do not interfere with phagocytosis.

“Brilliant green, like the hypochlorites, in the presence of serum, soon loses its value as a bactericide; hence, if used it must be renewed at frequent intervals. On the other hand, it possesses the advantage of being an extremely potent bactericide, far exceeding the flavins in watery solutions, while at the same time it is comparatively harmless to phagocytosis, as well as to the tissues locally, and when applied to a wound it is devoid of general toxic action on the body. Its use by two hourly flushings after the Carrel method, has proved most encouraging.

“The Dakin Solution. The value of this antiseptic has been demonstrated by Drs. Carrel and Dakin. It is a carefully standardized solution of sodium hypochlorite and is usually prepared from chlorinated lime (bleaching powder), but may be prepared directly from chlorine gas. The formula has been varied from time to time. Some surgeons use an acid solution (anærobes do not live in an acid medium), others an alkaline solution, while Drs. Dakin and Carrel in their method, avoid an excess of either quality. In the solution now used by them which is made according to the formula of Dufresne, the chlorinated lime is combined accurately with both sodium carbonate and sodium bicarbonate, making a nearly neutral product which contains from 0.45 to 0.5 per cent. of sodium hypochlorite, because less is too weak and more is too strong. The advantages of this solution are as follows: (1) It is antiseptic and does not damage the tissues. (2) It is non-toxic and no danger is to be apprehended from its absorption. (3) It is hypertonic, that is, the concentration of the solution is greater than that of blood serum and tissue fluids, and therefore, it produces an outflow of lymph. (4) If used as an acid solution it is available against anærobic bacteria which require an alkaline medium.

“The fact that nearly all wounds of the present war are infected, in connection with the serious and often fatal nature of the infection, has stimulated an unusual amount of research with the hope that a reliable and safe disinfectant may be discovered—especially one that will not injure the tissues of the body, since these are more easily affected by the disinfectant than the bacteria themselves. This object has been realized in large part by the Dakin-Carrel solution, which, however, to be effective, must be frequently renewed according to the Carrel technique. It is also frequently very irritating to the skin, although this may be avoided by the use of petrolatum.

“According to the investigation of Dakin, a chemical action takes place between the hypochlorite in the solution and the proteins in the wound exudate with the formation of the new substances called chloramines. One of these chloramines has been prepared synthetically and introduced under the name of chlorazene, which is said to possess a germicidal power four times greater than the Carrel-Dakin solution itself and is unirritating to the skin but, like the latter, must be frequently renewed. By dissolving one of these chloramines in an oily medium, however, it is possible to keep it in contact with the wound surfaces for a much longer time than can be done with a watery solution. The advantage of this is evident.

“The solution which is used at present has been named di-chloramin-T, the medium being chlorinated eucalyptus oil or paraffin oil. A ten per cent. solution of di-chloramin-T and eucalyptol may be kept in a colored bottle for at least one month with only slight change. It is applied to the wound surface in the form of a spray after the removal of infection foci and devitalized tissues. Deep cavities are filled with the liquid and drainage afterwards provided for. The high percentage of disinfectant contained in this preparation renders it active for a period of twenty-four hours because of the slow liberation of the germicide. It would appear that when applied with strict attention to detail it is not only less expensive than the Dakin-Carrel method, but will secure healing of a wound in a much shorter time. The gradual elaboration of the remedy makes it particularly applicable in cases that cannot be frequently dressed during transportation. Di-chloramin-T, hypochlorites and hypertonic salt solutions all have the power of dissolving dead tissue. A precaution to be remembered, however, is that if used near a blood vessel hemorrhage may occur.

“For a detailed report of the use of di-chloramin-T in the treatment of infected wounds, read Dr. H. T. Dakin’s article in the Journal of the American Medical Association, July 7, 1917. For a still later description of the Dakin-Carrel treatment of wounds, see the report of the Surgical Commission to the Directors General of the British Army Medical Service reprinted from the British Medical Journal, November 3, 1917.

“To my mind the best preparations that can be easily used are: (1) Chlorazene (Abbott), in tablet form; (2) in form of a non-irritating surgical powder containing 1 per cent. chlorazene; (3) in form of a cream containing 1 per cent. of chlorazene in a sodium stearate base. These I can recommend.”