PART FIRST. (continued 2)

In this way we may, in a pretty plausible manner, account for the origin of this distemper; viz. that it originally fell upon the Jews as a punishment for their iniquities; that from the Jews it has been at different times conveyed to other nations; and, by a mixture of those nations, has, at times, become general all over the world. At last it has, by the avarice of that people who first had been the occasion of its being introduced into the world, become permanent in Constantinople, whence it is still diffused among different nations in proportion to their dealings with that capital.

But it may now be said, ‘Allowing the positions contended for to be true in their utmost extent, how comes it to pass that the plague hath not been general in every age and in every country? Since the destruction of Jerusalem, the Jews have been dispersed over all nations: if nothing then were wanting to produce a pestilence but Jews and old clothes, no age or country ought to have been free from it; nevertheless it is certain that violent plagues take place only at particular times, with long intervals between; and of late the pestilential disposition seems to have become much less frequent than formerly; the western parts of Europe, particularly Britain, having been free from it for a great number of years. There must therefore be some cause, different from what has yet been mentioned, by which the infection is occasionally roused from inactivity, and excited to spread desolation all around.’

That there are predisposing causes to epidemic disorders, especially to the plague, the most fatal of them all, is not denied. These prepare the body for receiving the infection, but they will not, without that infection, produce the disorder. Of these causes so many are to be found in the conduct of mankind themselves, that we scarcely need to look for them any where else. In looking over the histories of plagues, we find them in an especial manner connected with famines and wars. The former sometimes take place in consequence of the failure of crops through natural causes; but, considering the general fertility of the earth, we must certainly account it owing to bad management, in some respect or other, that every country hath not as much laid up within itself as would guard against the consequences of at least one or two bad crops. Yet we believe there is not, at present, a country upon earth in this predicament. If a crop fails any where, the inhabitants must import largely, or they must starve. This is the case even in the fertile regions of the East, where the earth produces in excessive abundance,32 and there is little or nothing of any kind of provision exported to other countries. A remarkable instance of this occurred in the plague at Aleppo, a history of which is given by Dr. Russel. He tells us, that the winter of 1756 proved excessively cold, which was followed by a famine next year. This account is confirmed by Mr. Dawes, in a letter to the bishop of Carlisle.33 He tells us, that in the course of the winter many perished through cold; that the inhabitants were reduced to such extremities, by the single failure of the crop in 1757, that women were known to eat their own children as soon as they expired in their arms with hunger; and that human creatures might be seen contending with dogs, and scratching for the same bone with them in a dunghill. A dreadful plague followed; which, the two succeeding years, swept off not fewer than sixty thousand in the city of Aleppo.

It is probable that in this case the famine either produced the plague, or made it worse than it would have otherwise been; and it is not denied that the cold and bad season was the direct cause of the famine. But as little can it be denied, that had the people, or their governors, been so provident as to have laid up stores sufficient to supply the country for one year, this famine would not have been felt. As far, therefore, as the plague was connected with the famine, we must own that it was chargeable on the human race themselves; not the sins of this or that particular person, but a general deviation from the task assigned them by their Maker, viz. that of cultivating the ground; and, instead of this, spending their time in folly and trifling, to say no worse.

But famines are occasioned not only by natural causes, but by wars; in which mankind, acting in direct opposition to the laws of God and nature, destroy and lay waste the earth, taking every opportunity of reducing to extremity both those whom they call innocent and those whom they call guilty. Thus vast multitudes are reduced to want, to despair, and rendered a prey to grief, terror, and every depressing passion of the human mind; they are exposed to every inclemency of the weather; to the scorching heats of the day, and the chilling damps of the night; in short, to every thing that we can conceive capable of predisposing the body for the reception of diseases of the very worst kind. No wonder therefore that war and pestilence go hand in hand; and, by taking a review of the history of mankind, we shall see, that, always at those times when the nations have been most actively employed in the trade of butchering one another, then, or very soon after, they have been afflicted with pestilence. To begin with the great plague of 767 B. C. which coincides with the rise of the Assyrian empire: Till this time, though there had been numberless wars, yet they were carried on upon a much smaller scale than now, when great empires were to be set up, and when the most distant nations were to be assembled in order to gratify the pride and ambition of an individual. The Assyrians, we know, penetrated into Ethiopia; but how far east or how far west they went, we are not certainly informed. To their wars, however, we may with reason ascribe the desolations occasioned by this first plague. From Thucydides’s account of the plague at Athens, it seems plain that it was occasioned, or at least rendered more violent, by the wars of the Greeks with one another at that time. Had the Carthaginian army staid at home when they went to war with Dionysius, tyrant of Syracuse,34 it is very probable that the pestilence would not have broke out among them. The like may be said of the plague which broke out among them in the time of Marcellus.35 That in the time of Jugurtha, indeed, is said to have been occasioned by locusts; but, had not vast bodies of men been collected together for the purposes of war, the plague could never have committed such ravages. The plague in the time of Titus could not have been brought from Jerusalem, nor perhaps would it have existed there, had not Titus made war against that city; and so of others.

The plague which began in the reign of Justinian, as it was more violent than any recorded in history, so it was preceded by wars equally unexampled. The Romans had indeed for ages employed themselves in war; but, by their constant superiority to every adversary, their empire had become so amazingly extensive, that, whatever wars were carried on in the remote provinces, the great body of the empire always remained at peace; and this was the case even in their most violent civil wars. On the accession of Alexander Severus, about the year 232, they began to encounter enemies so numerous and formidable, that all their power proved insufficient to repel them. In the tenth year of Alexander’s reign, the Persians, having overthrown the ancient empire of the Parthians, turned their arms against the Romans, and, though frequently defeated at that time with great slaughter, renewed their incursions in the reign of Gordian, about the year 242, when they were in like manner defeated and obliged to retire. As these defeats, however, did not at all affect the strength of the Persian empire, the Romans still found them as formidable enemies as ever; while the Goths, Sarmatians, Franks, and other northern nations, harassed them in other parts. In the reign of Decius, who ascended the throne in 249, they became extremely formidable, insomuch that the emperor himself, with his whole army, was at last cut off by them. The consequence of this was, that the empire was instantly invaded in many different parts, and, though the barbarians were at times defeated, we never find that the empire regained its former tranquillity. The Persians and Scythians, taking advantage of the general confusion, invaded the provinces next them, while the finishing stroke seemed to be given to the Roman affairs by the defeat and captivity of Valerian by the Persians.

This disaster, as may well be imagined, produced an immediate invasion by numberless barbarians, while such multitudes of pretenders to the imperial crown were set up, each asserting his claim by force of arms, that the whole Roman territories were filled with bloodshed and slaughter. At this time Gallienus, the son of Valerian, was the lawful emperor, if indeed we may apply the word to the domination of such a monster. His mode of government may be imagined from the following letter written to one of his officers in consequence of a victory gained over an usurper named Ingenuus. “I shall not be satisfied with your putting to death only such as have borne arms against me, and might have fallen in the field: you must in every city destroy all the males, old and young; spare none who have wished ill to me, none who have spoken ill of me, the son of Valerian, the father and brother of princes. Ingenuus emperor! Tear, kill, cut in pieces, without mercy: you understand me; do then as you know I would do, who have written to you with my own hand.” In consequence of this horrible order, not a single male child was left alive in some of the cities of Mœsia, where this inhuman tragedy was acted.

In the midst of this dreadful commotion, we find the pestilence contributing its share to the common work of desolation. In Alexandria in Egypt, says Dionysius, bishop of that place, “fury and discord raged to such a degree, that it was more easy to pass from the east to the remotest provinces of the west, than from one place of Alexandria to another. The inhabitants had no intercourse but by letters, which were with the utmost difficulty conveyed from one friend to another. The port resembled the shores of the Red Sea strewed with the carcases of the drowned Egyptians: the sea was dyed with blood, and the Nile choked up with dead bodies. The war was attended with a general famine, and the famine with a dreadful plague, which daily swept off great numbers of people, insomuch that there were then in Alexandria fewer inhabitants, from the age of fourteen to that of eighty, than there used to be from forty to seventy.” It was not in Egypt alone that this calamity prevailed. It raged with great violence in Greece, and at Rome itself; where, for some time, it carried off five thousand persons a day. Many terrible phenomena of nature took place at the same time. The sun was overcast with thick clouds, and great darkness took place for several days, attended with a violent earthquake, and loud claps of thunder, not in the air, but in the bowels of the earth, which opened in several places and swallowed up great numbers of people in their habitations. The sea, swelling beyond measure, broke in upon the continent, and drowned whole cities.36

At last the civil commotions were settled by the accession of Claudius to the empire in 268. He found the Roman force so exhausted, that, when marching against the Goths, he wrote to the senate in the following terms: “If I should not be attended with success, you will remember that I fight after the reign of Gallienus. The whole empire is quite spent and exhausted, partly by him, and partly by the many tyrants who, during his reign, usurped the sovereignty, and laid waste our provinces. We want even shields, swords and spears.” In this miserable plight, however, he gained a most extraordinary victory; three hundred thousand of the enemy being killed or taken. But, while Claudius thus carried on the work of death successfully against the barbarians, he was attacked from a quarter where he could make no resistance: a violent plague broke out in his army, and carried off himself and a vast number of his men.

The dreadful defeat given to the Goths did not long preserve the tranquillity of the empire. New invasions took place, and new massacres ensued. At last, on the accession of Dioclesian to the empire, it was thought proper, on account of the present emergences, to divide such wide-extended territories into four parts, to be governed by four emperors of equal authority. By the activity and valour of these, particularly of one of them, named Galerius, the northern barbarians were repressed, and the Persians reduced so low, that they were obliged to yield up a great part of their territories; and it is said that their country might even have been reduced to a Roman province, had the emperor so inclined. We know not whether, in his eastern expedition, the Roman army received any infection, nor do we hear of any plague breaking out in it; but we are told that Galerius himself died of an uncommon distemper; an ulcer, attended with mortifications, violent pains, and the production of an infinite number of vermin, which devoured and tormented him day and night. This distemper, however, seems rather to have been a cancer than a pestilential disorder, as he laboured under it for more than a year. After his death, dreadful wars continued, both by reason of the incursions of barbarians, and the contests of those who enjoyed, or wished to enjoy, the empire. The eastern parts, however, had for some time kept free from pestilential contagion; of which the christian writers say, that Maximin, who reigned there, had made his boast; and, being a heathen, ascribed it to the care he took of preserving the worship of the gods. But, if this was really the case, he soon found his gods unable to protect him; for, soon after the accession of Constantine the great, and his embracing christianity, the dominions of Maximin were afflicted with famine accompanied with pestilence, and that attended by symptoms of a most extraordinary nature; particularly ulcers about the eyes, which rendered multitudes of those who were infected with the distemper totally blind. The christians did not fail to ascribe this plague to the sins of Maximin; but it must be observed, that to his other sins he had added that of involving himself in a violent war, during which the pestilence broke out, and which probably was one of the causes of it. We may likewise observe, that if the sins of Maximin brought on the plague, the piety of Constantine could not keep it off; since we find that in the year 332, a considerable time after the death of Maximin, the territories of Constantine were ravaged by a dreadful plague, and the famine was so severe, that, at Antioch, wheat was sold at four hundred pieces of silver per bushel. The distemper which put an end to the life of Maximin himself was indeed so extraordinary, that we may reasonably excuse those who called it a judgment sent directly from heaven. His eyes and tongue are said to have putrefied; “an invisible fire was kindled in his bowels, which, being attended with unrelenting torments, reduced him in a few days to a perfect skeleton; his whole body was covered over with a kind of leprosy, and devoured by swarms of vermin; he could not be prevailed upon to take any nourishment, but greedily swallowed handfuls of earth, as if he had hoped by that means to assuage his pains, and allay the hunger with which he was tormented without intermission.”37 All this, we are told, was the effect of poison, which he had swallowed in despair, after being defeated in battle; but the symptoms are unaccountable.

After the death of Constantine, the empire being again parted, civil dissensions took place; the northern barbarians and Persians renewed their incursions, and at length the battle of Mursa, between the emperor Constantius and an usurper named Magnentius, destroyed such numbers that the empire no more recovered its former strength. From this time therefore the wars with the barbarians became more and more violent; and, though frequently overcome, the advantage was ultimately on their side. In 361, the first year of the emperor Julian, the pestilence again made its appearance. It was accompanied by many other grievous calamities: Dreadful earthquakes were felt in every province; most of the cities in Palestine, Libya, Sicily and Greece, were overturned. Libanius writes, that not one city in Libya was left standing, and but one in Greece; that Nice was utterly ruined, and Constantinople greatly damaged. The sea, in several places, broke in upon the land, and destroyed whole cities with their inhabitants. At Alexandria, the sea, retiring during an earthquake, returned again with such violence, that it drowned several towns and villages in the neighbourhood. The earthquakes were followed by a famine, and the famine by a pestilence. It was observed by the christian writers, that the famine seemed to follow Julian from place to place: and no wonder that it did so; for he not only had always a large army along with him, which consumed great quantities of provision, but, attempting to remedy the evil by fixing the prices of provisions, he rendered it much worse, as the dealers in corn were thereby tempted to convey it to other places.38 Indeed this emperor seems to have been inclined to produce famines wherever he went; for, on his entering the territories of the Persians, with whom he was at war, he wasted the country to such a degree, that he could neither subsist nor return; while the enemy, imitating his example, destroyed all before him. The consequence was, that, by the time Julian was killed, the famine raged in the Roman camp to such a degree, that not a single person could have escaped, had not the enemy mercifully granted them peace.

Notwithstanding this dismal situation, we hear of no plague invading the camp of the Romans at that time. The wars, however, continued with great violence; and, in the time of Valentinian, Valens and Gratian, became worse than ever. The dreadful state of the empire in the time of Gratian is thus described by St. Jerom: “The whole country, from Constantinople to the Julian Alps, has been swimming these twenty years in Roman blood. Scythia, Thrace, Macedon, Dardania, Dacia, Thessaly, Achaia, both Epiruses, Dalmatia, both Pannonias, are filled with Goths, Sarmatians, Quadians, Alans, Huns, Vandals, Marcomans, &c. whose avarice nothing has escaped, whose cruelty has been felt by persons of all ranks, ages and conditions.” “What evils, (says Gregory Nazianzen) have we not seen or heard of! Whole countries have been destroyed with fire and sword; many thousand persons of all ranks and ages have been inhumanly massacred; the rivers are still dyed with blood, and the ground covered with heaps of dead bodies.”

In the midst of so great calamities, the pestilence, as an evil of inferior nature, might in many cases pass unnoticed by the historians of the times; nevertheless, even during that distracted period, we find some accounts of it. In 384 we are told of a famine and plague at Antioch; and, in 407, of one in Palestine, said to be occasioned by multitudes of grasshoppers, which even obscured the sun, and turned day into night. After having done incredible mischief, they were thrown by the wind partly into the Red Sea, and partly into the Mediterranean; whence being again cast ashore by the waves, they putrefied, and occasioned a pestilence. Two years after, when Rome had been first besieged by Alaric the Goth, the city was reduced to such straits, that human flesh was publicly sold, and some mothers are said to have devoured their children. This terrible famine was occasioned by the uncultivated state of the country, which had lain waste for several years, by reason of the wars, and the ports of Africa being blocked up by Heraclianus lest an usurper should become emperor; and thus this loyal admiral, for fear that the people should have a bad governor, determined rather that there should be no people to be governed. Notwithstanding this terrible famine, however, we hear of no pestilential disorder taking place; not even after the taking of the city by Alaric, when bloodshed and massacre were added to the other calamities.

All this time the empire, by the incursions of barbarians, by usurpations, civil wars, and the general licentiousness of the people, had been in a situation not to be described. The invasion of the Hunns, a new and more formidable enemy than they had ever experienced, now completed the ruin of the Romans. The whole western part of the empire became one continued scene of carnage and desolation. The common epithet bestowed upon Attila, the king of these barbarians, was, “The Scourge of God, the Destroyer of Armies.” As a specimen of his behaviour, we shall select the account of his taking of Aquileia in 452. That city, “being well fortified, and defended by the flower of the Roman troops, held out, in spite of his utmost efforts, for three months; at the end of which it was taken by assault, pillaged for several days together, and laid in ashes; not a single house being left standing, nor one person alive that fell into the enemy’s hands. The cities of Trevigio, Verona, Mantua, Cremona, Brescia and Bergamo, underwent the same fate; the barbarians raging every where with such fury as can hardly be expressed or conceived, and putting all to the sword, without distinction of sex, age, or condition.”39

Every one must own that this was a very effectual method of preventing the plague in those cities. It did not, however, prevent that, or some other diseases, from destroying such numbers of the tyrant’s troops, that he was for that time prevented from taking Rome itself. From this time, to the total extinction of the western empire, we do not hear of any remarkable infection taking place. The barbarians still continued their wars with one another, while the emperors of Constantinople were likewise at continual variance with the Persians. At last, in the year 532, they concluded what they called a perpetual or eternal peace, which lasted eight years! Other treaties and truces were concluded; notwithstanding which, the war was almost continual in the east; while, by the second conquest of Italy, and the invasion of the Gothic territories, new desolations overspread the west. Thus, for a great number of ages, mankind had been preparing themselves for the dreadful pestilence which was about to ensue. Whatever infection could be communicated to the air by multitudes of carcases rotting above ground had been done in an ample manner. Whatever debility could be communicated to the human frame by famine, exposure to the inclemency of weather, by fatigue, terror, grief, and every thing that can render life miserable, had also been communicated by the most powerful means. There only wanted something to begin the calamity; and this, whatever it was, took place in the fifteenth year of Justinian. Mr. Gibbon ascribes the origin of it to locusts; and its universality, to the general mixture of all nations, and the unrestrained intercourse they had with one another. “No restraints (says he) were imposed on the frequent intercourse of the Roman provinces. From Persia to France the nations were mingled by wars and emigrations; and the pestilential odour, which lurks for years in a bale of cotton, was imported, by the abuse of trade, into the most distant regions. Procopius relates, that it spread always from the sea-coast to the inland countries: the most sequestered islands and mountains were successively visited; the places which had escaped the fury of its first passage, were alone exposed to the contagion of the ensuing year. In time, its malignity was abated and dispersed; the disease alternately languished and revived; but it was not till the end of a calamitous period of fifty-two years, that mankind recovered their health, or the air resumed its pure and salubrious qualities.”

Thus Mr. Gibbon endeavours to explain the causes of this plague from an alteration in the salubrity of the atmosphere, without taking into consideration the dreadful commotions among mankind, above related. But, now that we have noticed two very general infections, one in 767 B. C. the other 1300 years after, we find them both preceded and accompanied by wars uncommonly violent and destructive. The great plague in the time of Justinian is said by Mr. Gibbon to have continued only fifty-two years; but this we must understand of its first and most violent attack; for it appears, from the testimonies produced in the former section, that pestilential disorders, even very violent ones, continued at intervals for several centuries. Thus, from the year 541 to 593, the space of fifty-two years is included; nevertheless, in the time of Phocas, who began to reign ten years after, the same calamity continued; as did also violent wars with the Persians and other barbarians.

The year 622 is remarkable for the flight of Mahomet from Mecca to Medina, from which time we may date the rise of the empire of the Saracens; a people who, for desolation and destruction, were perhaps never equalled except by the Hunns and Moguls. In 630 the impostor himself died, after having just united the Arabs or Saracens, and fitted them for the work in which they were to be employed. Their first exploit was, to fall upon the empire of Persia, now weakened by its endless wars with the Romans. This was conquered in two years; after which they broke into Palestine, and conquered the provinces bordering upon Syria. In 634 they reduced Syria itself and Egypt. In 636 they took and plundered Jerusalem. In 642 they conquered the African provinces, and reduced some of the islands in the Levant. With unabated fury they proceeded to the east and west; laying siege, in 668, to Constantinople itself, where they received their first check by the shipwreck of their fleet, and the defeat of their army. Thus, in the space of 38 years, the immense tract of country from the eastern part of Persia to the confines of the Mediterranean Sea, with the northern coasts of Africa, the whole including a space scarce inferior to the empire of Alexander the Great, was reduced under subjection to a race of savage barbarians, who knew only how to plunder, destroy, and reduce other nations to slavery.

In this manner were the eastern parts of the world prepared for a new infection, supposing the old one to have been entirely gone off. The Saracens pursued their good fortune, ravaged and conquered from India to Spain, and from Spain were proceeding northward through France, to extend their conquests to the other countries of Europe. But here, in 728, their fury was stopped by Charles Martel, the father of Pepin, and grandfather of Charles the Great. After a most obstinate and bloody battle, which lasted seven days, and in which the barbarians lost three hundred and seventy-five thousand men,40 they were driven beyond the Pyrennean mountains, and never after durst enter France. Thus was one fury stopped, only to give place to another. Charles, as ambitious and as cruel as the Saracens, having in vain attempted the conquest of Spain, reduced Italy and Germany; and, having dreadfully massacred the Saxons, and almost exterminated the Hunns, set up the German Empire, and was crowned emperor of the West in 800.

While the nations were thus deluging the earth with blood, the pestilence made its appearance in the east, attended with extraordinary phenomena.41 Some of these are taken notice of by the Arabian historians, and others are mentioned by them, concerning which the Greek histories are silent. In 636, particularly, we hear of violent storms of hail throughout the Arabian Peninsula, and of Syria being ravaged by epidemic distempers. It would seem, indeed, that the plague, during the whole of these horrible periods, had never been extinguished; for in 671 they tell us that a celebrated Arab, named Ziyad, died of the plague; though neither Greek nor Arabian historians take notice of any remarkable pestilence as raging at that time. We are told that this man was attended by no fewer than an hundred and fifty physicians.42 “But, as the decree was sealed, and the thing determined, they found it impossible to save him.” This distemper was attended with such an excruciating pain in his right hand, that the unhappy patient had recourse to a cadi, or judge, to inform him whether he might lawfully cut it off. The judge determined that it was absolutely unlawful to do so; notwithstanding which, Ziyad resolved to proceed: but his heart failed him when he saw the instruments and cauterising irons to be employed in the operation; for in those times of barbarity and ignorance they knew no other method of stopping blood but by a hot iron; and therefore some of the physicians in ancient times, when a limb was to be cut off, ordered the incision to be made down to the bone with a red hot razor. But, to return to our subject: In Syria and Mesopotamia swarms of locusts infected the earth about the year 679; but, as it seems extremely probable that the plague was never out of the eastern regions, we cannot expect to hear much of it, unless when extremely violent. That in the time of Constantine Copronymus seems to have extended over Arabia, as we are told that the Khalif Yezid, who was cotemporary with Copronymus, died of the plague. We are also told, that the earthquakes which afflicted the territories of the Greek emperors extended themselves to the countries about the Caspian Sea. In those ages indeed the phenomena of nature appear to have been so extraordinary, that we can scarcely account them any other than miraculous. Some of these have been described in the former section, on the authority of the Greek historians: the Arabians make mention of others similar. They tell us, also, that once or twice it rained black stones, and that some of these were so inflammable, that an Arab having attempted to make a fire with one of them in his tent, it burst out into such a violent flame as consumed the tent altogether.43 This rain may be accounted for from the explosion of a volcano; but how shall we account for the sun himself losing his light? a phenomenon acknowledged even by Mr. Gibbon; though that author huddles things together in such a manner as seems totally inconsistent with the regular chain of events. He tells us, that the dreadful plague, which broke out in the time of Justinian, was preceded by comets, and most violent earthquakes; and that these comets were attended with an extraordinary paleness of the sun. This may be; but the word paleness cannot apply to the darkness which lasted from the fourth of August to the first of October, and to which he seems to allude, though it happened long after the time of Justinian; neither can it be applied to what I am now about to relate, viz. that in the year 782, a little after sunrise, the solar light was lost without an eclipse, and the darkness continued till noon. It is impossible to read the histories of those times without remembering the words of our Saviour, that there should be signs in the sun and in the moon, distress and perplexity of nations, the sea and waves roaring, men’s hearts failing them for fear, &c. But, however the God of nature might thus intimate to mankind his displeasure with their proceedings, it is certain they made no alteration in their conduct. The Saracens, having conquered immense tracts of country, engaged in civil wars among themselves; the western nations, after having tried in vain to destroy each other, at last united in a romantic design of conquering Palestine from the Infidels; while the Turks, leaving their habitations about Mount Caucasus, where, like the vultures of Prometheus, they had for ages remained unseen and unknown, precipitated themselves upon the Greeks and Saracens, and lastly, as if all hell had broke loose at once, the Moguls, from the most easterly part of Asia, poured destruction upon the countries to the west, even as far as Russia and Poland.

All these events took place in a few centuries. In 844 the Turks quitted Mount Caucasus, and settled in Armenia Major. In 1030 they fell upon the Saracen empire, now divided among innumerable chieftains continually at war with each other. Among these was one called the Sultan of Persia, and another of Babylon. The former being worsted, called in the Turks to his assistance. They sent him an auxiliary army of only three thousand men; and from this slender beginning has arisen the vast empire of the Ottoman Porte. The three thousand men were commanded by a general called by the Greeks Tangrolipix, and by the Asiatics Togrul Beg. Being a man of ability, the Sultan of Persia, by his assistance, got the better of his adversary; but, refusing to let the Turks depart, Tangrolipix with his army withdrew to the desert of Carbonitis, where, being joined by numbers of discontented Persians, he began to invade the territories of the Saracens. The Sultan of Persia sent against him an army of twenty thousand men, whom Tangrolipix surprised and defeated, acquiring at the same time an immense booty. The fame of his victory, and his wealth, procured him bands of robbers, thieves, and blackguards, from all the neighbouring countries; so that he soon found himself at the head of fifty thousand. Against such a formidable force the Sultan of Persia marched in person; but happening to lose his life in the engagement by a fall from his horse, his men threw down their arms and acknowledged Tangrolipix to be Sultan of Persia.

The new sultan instantly thought of destroying other sultans and potentates; for which purpose he opened a passage for his countrymen from Armenia to Persia. The Sultan of Babylon was the first victim; after which Tangrolipix turned his arms unsuccessfully against the Arabians, but afterwards more successfully against the Greek emperors. The first invasion by the Turks took place in 1041; and in four hundred and twelve years they became absolute masters of the empire. Though unsuccessful at first against the Saracens, they prevailed greatly afterwards, and, by the time of the crusades, we find them masters of Palestine, as well as several other countries formerly conquered by the Arabs. From the time of their first invasion, in 1041, we may say, the war never ceased; and there is the greatest reason to suppose that the Greek empire would have been overthrown in a very short time, had not the crusaders checked their progress. The immense numbers with whom the barbarians had now to contend (amounting to no fewer than seven hundred thousand) threatened with destruction the newly erected empire of the Turks; and had it not been for the want of unanimity among the crusaders themselves, and the jealousy of the emperors of Constantinople, they certainly would have overthrown it. But, as matters went, all their labour was lost; and they only increased the general carnage and desolation to an extreme degree. The first crusade was planned in 1093, published in 1095, and in March 1096 the first army set out. In 1097 they began their conquests, but soon found it very difficult to keep them. The Turks being at home, and united, had many advantages over foreign invaders; which the latter endeavoured to counteract by drawing continual supplies of fresh men from Europe. Thus, for several centuries, the western part of Asia was rendered a scene of bloodshed and desolation. When they had contended for something more than two hundred years, Jenghiz Khan, the Mogul, seems to have formed the noble design of destroying the whole human race at once, excepting only his own immediate followers. His plan was, to exterminate man, woman and child wherever he went, and to plant the countries with his own people. It is impossible to do justice to his exploits. Voltaire, speaking of the irruption of the Moguls, says, that the people fled every where before them, like wild beasts roused from their dens by other beasts more savage than themselves. In the Universal History we are told, that he is supposed to have destroyed fourteen millions and an half of his fellow creatures. He died in 1227, and left successors worthy of himself. Some of these proceeded eastward, and some westward. The latter, under the conduct of a monster named Hula-ku, overthrew, in the year 1256, the remains of the Saracen empire, by the taking of Bagdad. The miserable Khalif, coming forth to meet his conqueror, was trampled under his horse’s feet, then sewed up in a sack, dragged through the streets, and thrown into the river. The Moguls who proceeded eastward invaded China. The Chinese resisted with innumerable multitudes, and battles were fought to which those of the present age are mere skirmishes. The soldiers, overcome with thirst, drank blood instead of water; hundreds of thousands fell on both sides, while human blood ran in streams for five or six miles. At last the fury of the Moguls was stopped by the ocean; for, having attempted the conquest of Japan, their fleet was wrecked, and an hundred thousand perished. Like other great empires, also, pretenders to the sovereignty started up, and the whole was parcelled out into a number of little states, which, of course, ceased to be formidable.

The decline of the Mogul empire did not restore peace to the world. The Turks continued their ravages; the western nations continued their crusades. England, which became a kingdom in 800, had been ravaged and conquered by the Danes and Normans, and likewise distressed by civil wars. At last, having emerged from its own difficulties, it began to inflict upon other nations the miseries itself had endured. Wales and Scotland became objects of the ambition of Edward I, who had already signalized his valour in the crusade. The Welsh were totally subjugated, and the Scots overthrown in the very bloody battle of Falkirk, where almost the whole force of the country was destroyed. The Scots, however, were never totally subdued. Robert Bruce retaliated on the English in the battle of Bannock-burn, where two hundred thousand English were defeated by thirty thousand Scots. But Robert was not contented with asserting the liberty of his country. Jealous of his brother Edward, he sent him with an army to conquer Ireland. We shall not doubt of his valour, or of the miseries he inflicted, or was willing to inflict, upon the people among whom he came. In destroying them he destroyed his own army. They were reduced to the most dreadful straits by famine, insomuch that they were obliged to feed upon the most loathsome matters, their own excrements not excepted.

Being now arrived at the beginning of the fourteenth century, we see that, from Ireland to China, mankind had involved themselves in one general work of destruction. Besides the wars, famines had been so frequent, that the eating of one another seemed to be but a common affair. Indeed the history of mankind would tempt one to believe that they thought themselves brought into the world for no other purpose but to destroy each other. As far back as the year 409, in the time of the wars of the Vandals in Spain, a dreadful famine took place, which, in 410, reduced many to the necessity of feeding upon human flesh; parents devoured their children, and the wild beasts, being deprived of the dead bodies which they used to feed upon, but which were at this time devoured by the living, fell upon the latter, and thus increased the general destruction. Such of the Romans as fled into strong holds and fortresses, were in the end obliged to feed upon one another. To these calamities the pestilence was added, which did not fail to rage in its usual manner. Famine and pestilence had also ravaged the city of Rome when besieged by the Goths under Vitiges, and under Totila. In this last siege the unhappy citizens were reduced to such straits, that they consumed even the grass which grew near the walls, and were at last obliged to feed on their own excrements. We do not indeed hear, at this time, of any particular instances of people feeding upon one another; though, in such dreadful emergences, it is scarcely to be doubted that some would have recourse to this terrible expedient in order to allay their hunger. But in the famines which took place during the ravages of the Saracens, Turks and Moguls, nothing seems to have been more common. In 1066 a most grievous famine took place at Alexandria in Egypt, and throughout the whole country. Three bushels and a half of flour were sold at eighty dinars, a dog at five, and a cat at three. The Visir, having waited on the Khalif, left his horse at the palace gate; but, before he returned, the animal had been carried off and eaten. Three men were hanged for this theft, and their bodies ordered to be exposed upon gibbets; but next day they were found picked to the bones, their flesh having been all cut off and devoured the preceding night. Bodies of men and women were boiled, and their flesh publicly sold. A violent plague followed, which swept away the greatest part of the inhabitants. As the hellish Moguls spread desolation wherever they advanced, so their retreats were equally formidable. In 1243, having advanced as far as Aleppo in Syria, they found themselves obliged to retreat, and that for a very odd reason, viz. that their horses were not well shod. This, however, did not hinder them from destroying every thing the earth produced, and stripping every man, nay, every woman, they met, even of their clothes. The consequence was, a terrible famine, so that people were fain to sell their children for small pieces of bread.

Such was the conduct of men, from one end of the earth to the other, during the interval, if any interval there was, between the plague in the time of Justinian and that of 1346. The pestilence, which had continually raged in one place or other, now overspread the whole world. At what time it began to decline we know not; and, indeed, as the same desolations and massacres continued, if these had any share in its production, it ought scarcely to have declined at all. That there was all this time little or no interval, appears from what Dr. Rush says, vol. iii. p. 165, that between the years 1006 and 1680, that is, in a period of 674 years, the plague was fifty-two times epidemic all over Europe. Supposing the intervals between every general infection then to have been equal, and the plague to have lasted only one year at a time, it must have recurred once in twelve years. But the intervals were not equal; for the Doctor tells us that it prevailed fourteen times in the fourteenth century; which gives an interval of less than seven years; and if the pestilence so frequently overspread the whole continent, we may be very sure that it never was out of particular places of it. The Doctor adds, “The state of Europe in this long period is well known.” We shall also consider that of Asia.

The empire of the Moguls, which had fallen into decay, revived under Tamerlane; who, following the example of Jenghiz Khan, had the epithet of the destroying prince bestowed upon him by the Indians, on account of his behaviour in their country. Building his captives into walls with stones and lime, pounding them by thousands in large mortars, was his common practice; while the Turks, proceeding westward, wasted every thing with fire and sword; the christians all the while continuing their mad crusades, and when driven from one place endeavouring to establish themselves in another. At last the Turks and Tartars, or Moguls, or rather their emperors, happening to quarrel, the battle of Angora, in Galatia, decided (at the expense of some hundred thousand lives) the dispute in favour of Tamerlane; but, as his empire ended with his life, the Turks soon recovered from the blow they had received; and, by the taking of Constantinople in 1453, put an end to the terrible commotions which had prevailed in the east for so many ages. The crusades had also for some time been discontinued, and the world hath since that time been comparatively in a state of peace.

But, by so much intercourse with the Asiatics, especially with the countries particularly subject to the plague, all Europe had been so deeply infected, that the distemper could not but prevail for a long time, even though it had not been kept up by the almost continual wars of the Europeans with one another, which was too much the case. Dr. Sydenham informs us that before his time the plague commonly visited England once in forty years; but by this we must understand a very violent infection; for Dr. Rush tells us that plagues prevailed in London every year from 1593 to 1611, and from 1636 to 1649. The author of the Journal of the Plague Year (1665) mentions a visitation in 1656; and Mr. Carey, in the beginning of his account of the plague of London in 1665, says, that the plague was almost continually among the diseases enumerated in their bills of mortality; so that we may fairly conclude it to have been endemic in that city. Now let us see how England had employed itself. Its kings, as well as many of their subjects, had gone to the holy wars, as they called them, and, by continuing in that devoted country where most probably the pestilence first originated, it is impossible to suppose that some of them did not receive the contagion. Having caught the pestilence in the holy war, they came home to diffuse it among their countrymen, and to keep it up by profane wars, I suppose, both foreign and domestic. Henry VII put an end to a very long and bloody contest between the houses of York and Lancaster; but he brought the pestilence along with him, which raged violently during the fifteenth and sixteenth centuries. A most violent war, for half a century, on the continent of Europe, and civil wars in England, would still continue to keep the infection alive from 1600 to 1648, when a general peace was concluded; and from the subsequent state of tranquillity, probably, after the violent attack in 1665, it seems to have languished and died in England, as a plant in a soil not natural to it.

But, though England has since remained in peace, on the continent it has been otherwise. In the beginning of the eighteenth century, the heroic madness of Charles XII seemed ready to confound the north, while the glorious exploits of prince Eugene and the duke of Marlborough appeared equally confounding to France. In the midst of these grand atchievments, the pestilence silently claimed its share in the common work of destruction; carrying off upwards of two thousand in a week for some time, in 1709, in the city of Dantzick, and, in 1711, twenty-five out of sixty thousand inhabitants in Copenhagen.

The infection, however, seemed now to be retiring to the place from whence it originally came. In 1666, or soon after, it seems to have totally abandoned the island of Britain; with the attack in 1711 it left the western countries of the continent next to that island; in 1713, 1714 and 1715 we are informed by baron Van Swieten that it ravaged Austria; in 1721, or soon after, it abandoned France; in 1743 it made its last attack on Messina; and in 1784 we find it confined to Dalmatia and the eastern territories, where it has so long reigned without interruption.

From the view then which we have taken of the conduct of the human race, and the consequences of that conduct, we may reasonably conclude, that war will produce famine and pestilence, and that after all violent wars a violent pestilence may be expected, especially if the contending parties interfere with those nations where it is most frequent. Another piece of conduct by which mankind expose themselves to pestilential contagions is, the practice of cooping themselves up in great cities. Mr. Gibbon, speaking of earthquakes, says, that men, though always complaining, frequently bring mischief upon themselves. “The institution of great cities (adds he) which enclose a nation within the limits of a wall, almost realises the wish of Caligula, that the Roman people had but one neck. In these disasters (earthquakes) the architect becomes the enemy of mankind. The hut of a savage, or the tent of an Arab, is thrown down without injury to the inhabitant; and the Peruvians had reason to deride the folly of the Spanish conquerors, who with so much cost and care erected their own sepulchres. The rich marbles of a palace are dashed on its owner’s head, a whole people is buried under the ruins of public or private edifices, and the conflagration is kindled and propagated by innumerable fires necessary for the subsistence and manufactures of a great city.” In plagues, great cities are unquestionably as pernicious as in earthquakes; not indeed by reason of the weight and bulk of the materials, but the confinement of the people within the sphere of infection, and their continual exposure to the causes which prepare the body for receiving it. In fact, it has always been found that plagues begin in cities; and were it not for the multitudes that continually fly out of them there can be no doubt that the mortality would be much greater than it is. The intercourse of many nations with one another, the carrying from one end of the earth to the other of goods capable of bringing with them the infection, must also be supposed a very principal cause of pestilence; but this last will be more fully considered in the next section. At present we may conclude, that, the pestilential contagion having originally fallen upon mankind for their sins, it is still kept alive by the same causes; and, as far as we can conjecture, these sins are, the propensity to murder and destroy which breaks forth in war; the vanity, pride and luxury which produces great cities; and the same vanity, &c. joined with avarice, which gives life to commerce. Add to all this the neglect of the cultivation of the earth, which ought to be the principal business of man. In consequence of this neglect, immense tracts of it are still overrun with woods, covered with stagnant and noxious waters, or lying in waste and now uninhabitable deserts, fit only for serpents and the most destructive animals. Thus the very climate is changed from what it ought to be; the elements become hostile to man in an extreme degree, and the whole system of nature, originally designed to give life and happiness to the human race, is, through their own misconduct, changed into a system of misery, disease and death.

The account just now given of the ways in which mankind bring upon themselves the plague, and other diseases almost equally terrible, is so conformable to the opinions of the learned Dr. Mead, that I shall conclude this section with a few extracts from his works. Of the small pox he says, that he supposes this “to be a plague of its own kind, originally bred in Africa, and more especially in Ethiopia, as the heat is excessive there; and thence, like the true plague, was brought into Arabia and Egypt, after the manner above mentioned” (i. e. by war and merchandise.) “Now (adds he) if any one should wonder why this contagion was so long confined to its native soil, without spreading into distant countries, I pray him to consider, that foreign commerce was much more sparingly carried on in ancient times than in our days, especially between Mediterranean nations; and likewise that the ancients seldom or never undertook long voyages by sea, as we do. And Ludolfus observes, that the Ethiopians in particular were ignorant of mercantile affairs. Therefore when in process of time the mutual intercourse of different nations became more frequent by wars, trade and other causes, this contagious disease was spread far and wide. But, towards the end of the eleventh century, and beginning of the twelfth, it gained vast ground by means of the wars waged by a confederacy of christian powers against the Saracens, for the recovery of the Holy Land; this being the only visible recompense of their religious expeditions, which they brought back to their respective countries.” Of the true plague he says, “It appears, I think, very plainly, that the plague is a real poison, which, being bred in the southern parts of the world, is carried by commerce into other parts of the world, particularly into Turky, where it maintains itself by a kind of circulation from persons to goods; which is chiefly owing to the negligence of the people there, who are stupidly careless in the affair: that, when the constitution of the air happens to favour infection, it rages there with great violence; that at that time, more especially, diseased persons give it to one another, and from them contagious matter is lodged in goods of a soft, loose texture, which, being packed up and carried into other countries, let out, when opened, the imprisoned seeds of the contagion, and produce the disease whenever the air is disposed to give them force; otherwise they may be dissipated without any considerable ill effects. The air of our climate is so far from being ever the original of the true plague, that most probably it never produces those milder infectious distempers, the small pox and measles. For these diseases were not heard of in Europe before the Moors had entered Spain; and, as already observed, they were afterwards propagated and spread through all nations, chiefly by means of the wars with the Saracens. The sweating sickness was most probably of foreign original. It began in the army with which king Henry VII came from France, and landed in Wales; and it has been supposed by some to have been brought from the famous siege of Rhodes, three or four years before, as may be collected from one place of what Dr. Keyes says in his treatise on the disease. We had here the same kind of fever in 1713, about the month of September, which was called the Dunkirk fever, is being brought by our soldiers from that place. This, probably, had its original from the plague which broke out at Dantzick a few years before, and continued some time among the cities of the north.”

I now take leave, for the present, of this subject, which exhibits the conduct of mankind in such a disagreeable view. Some, like M. Millot above quoted, may be apt to suppose that many of the accounts are exaggerated. But it is evident, that in our days it is impossible to determine any thing to be a falsehood, said to have happened in former ages, which is not absolutely contradictory to reason. Every one of the accounts inserted in this section has found a place in the works of historians reckoned authentic, particularly in the Universal History. All who believe the New Testament must certainly believe, from the words of our Saviour, that extraordinary things were to happen in the ages subsequent to his appearance. Can we then discredit the relations of those historians who inform us that extraordinary things have happened? Modern historians, making their own judgments the infallible measure of wisdom, and the strength of nations now existing the ultimate measure of human power, have endeavoured to turn into ridicule every thing which does not precisely accord with these two. In this the French are particularly culpable; accounting every thing to be incredible which exceeds the power of modern France to accomplish, though they certainly do not know even the extent of this power. Of such scandalous vanity we have a notable instance in the works of president Goguet, who positively determines that the walls of ancient Babylon, the pyramids of Egypt, and all the wonderful works of Semiramis, Nebuchadnezzar, &c. were not equal to the canal of Languedoc made by Louis XIV!

SECTION III.

Of Disease in general.—The nature of the Plague as a Disease considered.—Of Contagion.—Whether the Plague is really Contagious or not.—Medical History of the Distemper.—Inquiry into its Immediate Causes, and whether an approaching Plague is indicated by any visible Signs.

HITHERTO we have considered the origin of the plague entirely in a moral point of view. We have seen, that, in conformity to the general opinion of mankind, it may reasonably be supposed to have been inflicted upon mankind, the Jews particularly, for their transgressions; that, having been once introduced, it has been perpetuated, and spread from nation to nation, and that in proportion to the degree of immorality of a certain kind prevailing through the world. From this it is naturally to be inferred, that, were the human race to live at peace with one another, to disperse themselves over the face of the earth for the purpose of improving it by cultivation, and were they to be contented with what the produce of each country affords, there would be no plague among them. But we know that such a reformation is not to be expected, and we must take the world as we find it. The question then is, By what means shall individuals secure themselves from being destroyed by a plague which shall happen to invade any country; or how shall a person, already infected with it, be restored to health? For this purpose let us begin with considering the nature of disease in general, and of the plague particularly.

As to disease in general, physicians have differed very considerably in their definitions; and, though many have been given, few seem to be unexceptionable. That of Dr. Fordyce seems to be among the clearest and most expressive. “Disease (says he) is such an alteration in the chemical properties of the fluids or solids, or of their organization, or of the action of the moving powers, as produces an inability or difficulty of performing the functions of the whole or any part of the system, or pain, or preternatural evacuation.” But as this definition, however just, cannot be easily understood by such as are unaccustomed to medical language, I shall attempt the following explanation of the animal economy, and the diseases to which it is subject.

1. By nature our bodies are formed of certain solid and fluid parts, operating upon one another in a manner of which we know but little. Anatomists have described the structure of the human body and its parts in a certain degree, but have always found themselves lost in an inconceivable minuteness of texture. The whole structure of the human body, visible and invisible, is called its ORGANIZATION.

2. This organized body is acted upon by certain powers residing in the atmosphere, by which it becomes endowed with LIFE.

3. The operation of those powers upon a well organized body constitutes that agreeable and vigorous state which we call HEALTH.

4. The operation of any other power, substituted in place of the natural one, even upon a body perfectly organized, produces a state very different from health; commonly attended with some uneasy sensations, and which is called DISEASE. I say it is commonly attended with uneasiness, but not always; for many persons within a few hours, nay, a few minutes, of their death, have imagined themselves quite recovered and well. To illustrate the meaning of what is said of the substitution of any power instead of the natural one: It is natural for man to breathe air of a certain quality; and while he does so he continues in health; but let him breathe the vapour of burning charcoal, or of fermenting liquor, mixed in considerable quantity with the air to which he has been accustomed, and he will very soon find himself diseased. Many other kinds of elastic fluids may be substituted instead of the vapour just mentioned, all of which will in a short time produce a disease in the most healthy man. The state of a diseased body being very different from that of a sound one, the appearances are consequently very different. The various appearances of disease in the human body are called symptoms of that disease, from a Greek word signifying appearance.44

5. A disease proves mortal only by the DISORGANIZATION of the body. By disorganization I mean any considerable alteration in the structure of the body, visible or invisible. The truth of this will appear from a consideration of the method by which animals may be recovered, after being to appearance dead by breathing the vapour of charcoal, or fixed air in any other form, viz. by plunging them in cold water. In a cave in Italy a continual stream of this kind of air issues from the ground. It rises but a small way, so that a man may safely enter, because his head is above the vapour; but, if he brings a small dog with him, the animal, in consequence of breathing the pernicious fluid, falls down as if dead, and would very soon die if left there. By throwing it into a lake in the neighbourhood, (cold water of any kind would answer as well) it recovers. In the dissection of some unfortunate people, who have been killed by breathing this pernicious fume, a manifest disorganization has been observed, viz. a rarefaction of the blood, and too great dilation, or even rupture, of the small vessels.

6. A disease cannot always be cured by removing the cause which brought it on: it is necessary also to repair the injury done to the organization. This is exemplified in the case of the dog just mentioned. Taking him out of the vapour is not sufficient for his recovery, because the organization of the body is injured; the cold water by contracting the vessels repairs the injury, and the cure is completed. To the entire preservation of this organization it is probably owing, that people have frequently recovered after being thought dead for a long time.45

7. When the organization of the body is injured, the action of the natural powers themselves occasions uneasiness, and increases the disease. The cure then is, to substitute instead of the natural power, as far as possible, the action of some other power till the organization is restored; after which the natural power must be again allowed to act, or a disease of another kind will take place. This may be exemplified in a consumption of the lungs; where, that part being very much disorganized, pure air renders the disease worse; and the sick are relieved by mixing with the common atmosphere such kinds of air or vapour as would prove pernicious to people in health. But, supposing this method to be successful, and the consumption to be entirely removed, it is plain that the use of the pure atmosphere must be resumed, or the impure air would bring on a disease in the same manner as on a healthy person.

8. The body is wasted in the natural operations of life; part of it passing off with the vapour of the breath, part by insensible perspiration, &c. Hence it naturally tends to disorganization and death, unless the waste be repaired.

9. This natural waste of the body is repaired, and health kept up, by the food and drink taken into the stomach.

10. Hence arises another set of diseases; for as the reparation of the waste, just mentioned, depends on the proper action of the stomach upon the food, and the assimilation of the latter with the substance of the body, it is plain that this operation depends both on the proper quality of the food, and the sound state of the stomach itself.

11. The body is composed of solids and fluids of different kinds, every one of which is subject to diseases peculiar to itself; but, by reason of the connexion of the parts of the body with one another, it is impossible that any one can be very much disordered without affecting all the rest. As the bond of connexion, however, is in many cases totally invisible to us, surprising instances frequently occur of one part being affected in consequence of an injury done to another very distant from it. This connexion between all parts of the body is called SYMPATHY. Dr. Gardiner of Edinburgh, in his observations on the animal economy, &c. says, that “the stomach is the principal seat of many of the most remarkable sympathetic affections which happen in valetudinary states of the body. Every disorder accompanied with severe pain affects the stomach, whilst this viscus affects not only in its diseased state every part of the system, but at other times the effects of healthful stimuli applied to it are instantly communicated to the rest of the body, as when we take food, wine, or medicine.” Dr. Darwin in his Zoonomia informs us that the stomach is said to sympathize with almost every part of the body; but Dr. Moore, in his medical sketches, tells us that the heart possesses a greater share of sympathy than any other part in the body, and next to it the stomach.46

12. The solid parts of the body are the bones, the muscles, brain and nerves; the fluids are, the blood, and others produced from it. The bones are known to every one; the muscles are the fleshy parts throughout the whole body; and the nerves are a kind of cords seemingly originating from the brain, and from thence accompanying the blood vessels through all parts of the body.

13. Much has been disputed about what is to be accounted the primary part of the body, on which all the rest depend; and one class of disputants have arranged themselves on the side of the blood, and the other on that of the nerves. The dispute is like one about the beginning of a circle. It cannot be decided, because the blood cannot act without nerves, nor the nerves without blood. I speak of the human body, being aware that in some animals the position may be controverted. The following is a concise state of the matter.

14. All the blood in the body passes through the heart; which has four cavities; two called ventricles, and two auricles. These, from their position in the body, are called the right and left. The right ventricle communicates with the right auricle, as does also the left ventricle with the left auricle; but there is no communication between the right ventricle and the left, nor between the right auricle and the left. Through these cavities all the blood passes to every part of the body, and returns from every part; but, as in the former case, we are here at a great loss where to begin its motion; for this is precisely to find the beginning of a circle. As we must begin somewhere, however, we shall do so with the right ventricle of the heart. This receives the blood returning from all parts of the body, and propels it into the right ventricle; not the whole quantity at once, for it cannot contain one half of it; but by degrees. The auricle contracts as soon as it is full; and in the time that the auricle fills, the ventricle contracts, so that it may be empty, and ready to receive the blood from the auricle. By the contraction of the right ventricle the blood is driven into the pulmonary artery, and passes into the lungs. Here the artery branches into an infinite number of small vessels much finer than hairs; and these again, uniting into larger trunks, form at last the pulmonary vein, which brings back the blood to the heart. The pulmonary vein is inserted into the left auricle of the heart, which, as soon as it is filled with blood, contracts, and expels the blood from it into the left ventricle. From the left ventricle issues a large artery called the aorta, which by its branches supplies the whole body with the vital fluid. In all parts of the body the arteries divide themselves into innumerable small branches, which terminate in veins equally small as in the lungs; but it has been disputed whether the arteries and veins actually join each other in the form of vessels, or whether the arteries deposit the blood in small cells, from which the veins suck it up. The dispute is of no consequence, nor can it be absolutely decided, on account of the exceeding smallness of the vessels; though the microscopical observations are rather favourable to the opinion of a continuation of vessels. The veins from all parts of the body unite into larger vessels, and these again uniting with one another, form at last one very large vein called the vena cava, which opens into the right auricle of the heart, from which the circulation goes on as already described. The two ventricles of the heart, and all the veins throughout the body, are furnished with a kind of valves, which allow the blood to proceed in the way of circulation, but prevent its returning in a contrary direction.

15. The lungs, through which all the blood in the body passes, receive likewise the air which we draw in every time we breathe. They consist of two large bodies called lobes; from their situation called the right and left. The air is conveyed into them by the wind-pipe, called also the trachea, and the aspera arteria. On entering the cavity of the breast, the wind-pipe divides into two large branches called the bronchiæ; one of which goes to the right and the other to the left lobe of the lungs. By the further division and subdivision of these vessels the lungs are filled with an innumerable multitude of little tubes, terminating in exceedingly minute bladders or cells, which are the final receptacles of the air sucked in when we breathe. Each of these cells is surrounded with a kind of network of blood-vessels exceedingly small, and consisting of very thin membranes; so that, in passing through the lungs, the blood is exposed as much as possible to the action of the air.

16. It is a matter of great importance to find out what is the use of this exposure of the blood; and great disputes have taken place concerning it. In former times it was supposed that the blood received from the air a vital spirit, without which it would have been totally incapable of performing its offices in the body. Later physiologists endeavoured to explode this notion. Dr. Hales particularly, by shewing that the circulation of the blood through the lungs might be continued by inflating and contracting them alternately by the fumes of burning brimstone, endeavoured to prove that the use of the air was only to give the lungs an opportunity of dilating and contracting alternately, by which means principally he thought the circulation might be carried on. This continued to be the most common hypothesis as late as the time of Dr. Huxham. It was however thought also that by the compression of the air the blood was altered in its texture, its bulk, &c. Accordingly Dr. Huxham tells us in the preface to his treatise on air and epidemic diseases, that “air fit for respiration ought neither to be too hot, nor very cold; for the use of the inspired air is to temperate the blood, which would otherwise grow too hot, and putrefy, as is evident from the experiment of the most excellent Boerhaave made in a hot house; for, if the air is more hot, or even equally hot, as the blood of any animal, it certainly soon dies.”47

17. The modern discoveries in the composition of air, have tended greatly to elucidate the use of this fluid in the lungs, and its action on the blood in respiration. Dr. Priestly first determined it to be what he terms a phlogistic process, i. e. a process by which the parts of the blood no longer proper to be retained among the rest, or at least some of them, are carried off. That something is carried off either from the lungs themselves, or from the blood circulating through them, is evident; for the air which is taken into the lungs in a dry state, comes out of them extremely moist, and loaded with vapour. An essential change is also made in the nature of the air itself; for it now assumes in a great measure the nature of what has been called fixed air, or the fume of charcoal, or fermenting liquor, and thus becomes unfit for being breathed a second time. This change is made by the addition of some terrestrial substance to the pure atmosphere, which the latter volatilizes and carries along with it.48

18. But, whatever may be carried off from the blood, during its passage through the lungs, something is certainly added to it, for the blood in the pulmonary artery is of a dark red, but when it has undergone the action of the air in the lungs, and returns by the pulmonary vein, it is then of a bright scarlet, which colour it retains through all the arteries of the body, but loses it on its return through the veins. This scarlet colour is communicated to blood in all cases when exposed to the air; and Dr. Priestley has observed that it is acted upon by the air even through a bladder; much more then must it be so through those very thin membranes which form the coats of the fine pulmonary vessels. What this subtile matter is which the blood receives, shall be afterwards inquired into; at present it is sufficient to take notice that it is absolutely necessary, for the purposes of life, that the blood should pass through the lungs: for, as Dr. Huxham observes, “we see neither nutrition, nor the motion of the muscles, performed by any blood that hath not passed through the lungs; this is observable from the coronary arteries49 to the ultimate ramifications of the aorta.” As the previous circulation of the blood through the lungs therefore is absolutely necessary to the growth and life of the body, and as the blood certainly receives something from the air, we must account this a proof, and no inconsiderable one, that the air contains a vital spirit, which it imparts to the blood in the lungs. But, before we proceed farther on this subject, it is proper to take some notice of

19. The nerves. These, which constitute such a remarkable and important part of the human body, are white cords, of a soft pulpy substance, defended by a tough skin which goes along with them as far as they can be traced. All the nerves either originate from the brain, or terminate in it. The former doctrine hath been generally adopted, and in conformity to that doctrine the following account of the nerves is laid down. The brain is enclosed in the cavity of the scull, but not without the intervention of two membranes, called the dura and pia mater, to prevent injury from the hard bones, as well as for other purposes. The brain is divided into two lobes, the right and left. It is composed of two different kinds of substance, the outermost called the cortical, the innermost the medullary substance; the latter seems composed of fine fibres. The whole of the medullary part of the brain terminates in a substance called the cerebellum, very much resembling the brain, but smaller. The cerebellum terminates in another substance resembling the medullary part of the brain, called the medulla oblongata. The cerebellum lies in the back part of the head, and the medulla oblongata under it. The latter terminates in the spinal marrow, extending from the lower and back part of the head to the lower extremity of the back bone, and is enclosed in the hollow of that bone. The nerves proceed from these four substances, viz. the brain, the cerebellum, the medulla oblongata, and spinal marrow. As they pass to all parts of the body they accompany the arteries, dividing with them into innumerable small branches; but they do not return with the veins; so that they seem not to contain any fluid which goes and comes, or which circulates like the blood. The nervous fluid, if any such there be, seems to move constantly one way, either to the brain or from it.

20. Hitherto we have noticed only things which are evident to our senses, and which the industry of anatomists has abundantly evinced; but now our subject renders it necessary to step aside a little into the obscure regions of theory and conjecture. The muscles, as we have formerly said, are the fleshy parts of the body; and by them all the motions of the body are performed. The flesh is distributed into distinct portions, each of which is enclosed in a membrane belonging to itself. Each of these portions is a muscle, and each muscle has a branch of an artery and the branch of a nerve belonging to it. On both these the action of the muscle depends; for, if we cut the nerve belonging to a muscle, it immediately loses all power of action; and if we cut the artery which accompanies the nerve, it does the same. As therefore the blood is found to receive something from the air, and as it loses this when passing through the arteries, and as the nerves lose their power when the communication with the blood is cut off, it seems extremely probable, that what is imbibed by the blood in the lungs is taken up by the fine ramifications of the nerves, and is no other than the immediate principle of life and sensation. Thus we will establish a doctrine directly opposite to that commonly received; for, instead of supposing that the nerves originate from the brain, we are now led to suppose that they terminate in it. Instead of supposing that the sensations originate in the brain, we will be led to suppose that every sensation originates in the organ appointed for that sensation. Thus we are conscious that our eyes, not our brain, are the parts of our body which immediately perceive the light; our fingers, or any other parts of the body, feel what is applied to them; and of consequence we have reason to believe that the animal spirits, nervous fluid, or whatever we please to call it, proceed from the surface of the body inwards to the brain, not outwards from the brain to the surface of the body. The brain itself seems to resemble a large collection or reservoir of water, in which the sensations, like so many small streams from every part of the body, unite, and in which our intellectual faculties reside in a manner totally inexplicable by us. Thus far it seemed necessary to theorise, in order to form some idea, however obscured, of the connexion between the nerves and our sensitive and intellectual, or, if we please to call them so, our spiritual faculties.

21. In consequence of this very intimate connexion between the blood and nerves, it is easy to see that any injury done to the one may very greatly affect the other; and that a very slight, nay, to us imperceptible, change in the organization of either, may produce the most grievous, and even incurable disorders throughout the whole body, or in any particular organ. Let us now consider a little farther the blood-vessels.

22. It hath been a question, whether in the structure of these vessels nature hath observed an exact proportion. For instance, if the blood passes by a kind of starts through four cavities, as we are assured that it does, it seems natural to suppose that these four should be exactly equal. This, however, hath been denied; and some, from its accommodating the human frame to their theory, have fancied that they saw the use of such disproportionate work. Dr. Huxham expresses himself in the following words: “Nor doth the air only refrigerate the blood, but, by preventing its too great ebullition, and condensing it, hinders it from bursting the vessels. This indeed is of exceeding great importance, if, with the very learned Helvetius, we suppose the capacity of the right ventricle of the heart to be greater than that of the left, and that the pulmonary arteries are larger than the correspondent veins; for it thence follows, that the blood ought to be considerably condensed by the inspired air, that an equal quantity of blood may be received, in one and the same time, by the pulmonary veins and left ventricle of the heart, that is thrown off from the right ventricle, and through the more capacious pulmonary arteries. This indeed many deny, asserting quite the contrary. It is necessary, however, that the aorta should receive as much blood from the left ventricle of the heart, as is thrown off from the right ventricle through the pulmonary artery; and that in the very same and equal time, or a fatal deluge would soon overwhelm the lungs, because the contraction of each ventricle is made at one and the same time; we always find therefore the aorta and pulmonary artery, in a natural state, equal on this account; also the capacity of the ventricles ought to be equal, that they may receive, in one and the same space of time, equal quantities of blood,” &c.

If any thing farther is necessary upon this subject, we may still observe, that if the blood were at all condensed by the air, it would be so unequally, because the air is at some times much colder than at others; and thus the disproportion of the cavities of the heart to one another could not fail of producing the most disagreeable if not fatal effects. We often see what terrible consequences ensue upon the enlargement of any part of an artery near the heart; and these would, sometimes at least, be felt by every individual.50

It is true, indeed, that this objection will in some degree hold, even though we suppose all the cavities of the heart to be equal, and the capacities of the blood vessels to be perfectly uniform throughout the whole body. For, if we suppose the blood to be at all condensed in the lungs by the coldness of the atmosphere, it must undoubtedly follow, that while passing from them it occupies less space than before it arrives at them. Hence the pulmonary vein, the left auricle of the heart, the left ventricle, the aorta, and all the rest of the arteries for a considerable way, must be comparatively empty, even though they receive as much fluid as fills the vena cava, right auricle and ventricle of the heart, and pulmonary artery. The equality which ought to prevail in the system, and which indeed cannot be dispensed with, can only take place in those remoter branches of the arteries in which the blood has reassumed its former state of dilation or rarefaction.

23. If we consider this matter attentively, we shall find it not a little mysterious. Every time we breathe out the air we have sucked into our lungs, a considerable quantity of moist vapour is breathed out along with it; but it has been proved by undeniable experiments that the emission of aqueous vapour from any substance cools it in proportion to the quantity of vapour emitted. Every breath we draw, then, cools the lungs, and consequently the blood, to a certain degree, and, as the number of times that we breathe in a day is exceedingly great, the cold produced by the evaporation ought to be in proportion. But we see that, notwithstanding all this cooling, whether we breathe cold air or hot air, the temperature of the body remains still the same. The air then, though constantly carrying off the heat of the body, does not cool it in the least by its action on the lungs. The only possible way of solving this apparent contradiction is, by supposing that the air, when acting upon the blood in the lungs, leaves precisely as much heat as it carries off, and therefore, though we breathe ever so long, we cannot by this means become either hotter or colder.

24. To illustrate this subject, we might now enter into an inquiry concerning the origin and cause of animal heat; but this will be touched upon hereafter. We shall here only take notice that the heat of the body is almost universally allowed to proceed from the lungs. It has likewise been demonstrated, that the air does in fact contain an incredible quantity of heat, even when it appears to us to be extremely cold. A certain proportion of this heat is separated from it every time we breathe; and if, either by the mixture of other fluids with the air we breathe, or by any change in the organization of the body itself, a greater or smaller proportion of heat should be communicated to the blood, disease must ensue.

25. To sum up then what has been said concerning the blood and nerves: The whole mass of fluid passes from the right side of the heart to the lungs. In the lungs it receives from the air something52 necessary to the functions of life and sensation, and purifies itself from those matters which might prove pernicious. From the lungs it passes to the left side of the heart, and thence through the whole body. In its passage through the body, it is accompanied with nerves, which, taking up from the arterial blood that vital spirit received from the air, convey it to all the organs of motion, of sensation, and to the brain, where the whole powers of perception being united form our intellectual faculties, and, as far as our senses can perceive, the human spirit itself. The blood, thus deprived of its spirit, is collected from all parts of the body by the veins, and returned to the right side of the heart, from whence it is again sent to the lungs, and the process carried on as before. This hypothesis concerning the peculiar function of the nerves I first inserted in the Encyclopædia Britannica, second edition, under the article Blood, in the year 1778. It has been since continued in the third Scots edition, and from thence into the Irish and American editions.

26. It has already been observed, that the body is subjected to a continual waste. One source of this waste is the breath, by which a considerable part passes off in vapour. A great quantity also passes off by the pores of the skin; frequently in a perceptible liquid called sweat, but oftener in an invisible vapour from all parts of the body, called insensible perspiration. The latter has been thought to be the great source of waste to the human body; and it is certain, that if any person in health be weighed when he rises in the morning, he will be found considerably lighter than when he went to bed. The loss of weight in this case proceeds not only from the pores of the skin, but from the lungs; but though physicians have made a general allowance for both these, I have not heard of any experiment by which we can determine how much passes off by the one, and how much by the other, nor indeed does it appear easy to make such an experiment. Galen plainly overlooks the perspiration from the lungs entirely. “This excrementitious vapour (says he) is expelled through small orifices, which the Greeks call pores, dispersed all over the body, and especially over the skin, partly by sweat, and partly by insensible perspiration, which escapes the sight, and is known to few.” Sanctorius, and the succeeding writers, have classed both together indiscriminately; allowing the discharge to be so great, that if eight pounds of aliment be taken in, five of them pass off in this manner. In a system of anatomy, published at Edinburgh in 1791, the author says, that the discharge by the skin “is even much larger than this (the discharge from the lungs we may suppose) since it not only throws off a quantity of the aliment, but likewise what is added to the blood by inhalation, which, entering often in a very considerable quantity, is thus again expelled.” The same author likewise says, that the “perspirable matter from the skin is principally water,” and that it issues in such quantity as to be seen in subterraneous caverns evidently flying off from the surface of the body like a dense vapour. But other physiologists, particularly Dr. Blumenbach, inform us, that the matter of insensible perspiration is quite similar to the discharge from the lungs, particularly containing a great quantity of fixed air. The same account is given in Chaptal’s chemistry, on the authority of Messrs. Milly and Fouquet. This may be looked upon as a valuable discovery, especially in conjunction with that related by Drs. Beddoes and Girtanner, viz. that the flesh of animals contains a quantity of oxygen. Dr. Girtanner obtained a quantity of this air from the raw flesh of animals, and says that it may be repeatedly obtained by exposing the flesh to the atmosphere, and distilling with a heat of 60 or 70 degrees of Reaumur’s thermometer (something below that of boiling water.) Hence it is natural to conclude, that, as the discharge from the lungs purifies the blood from its useless parts, so does the insensible discharge from the skin purify the solid parts from those particles which are no longer useful. The probability of this also becomes greater by considering, that in diseases, when the quantity of matter to be thrown off is very great, the skin becomes foul, the teeth furred with black sordes, &c. all which disappear as soon as the quantity of the offensive particles is reduced to its natural standard. As to any considerable quantity of aqueous vapour being discharged this way, unless in case of sweat, it does not seem probable; for in such a case our clothes would always be moist; and in the night time the accumulation of moisture would certainly be perceptible. The sweat is entirely of a different nature from the insensible perspiration, and blood and even sand has been known to issue through the skin along with it. (See the Anatomical System above quoted.)

27. This very considerable waste of the body is repaired by the aliment taken into the stomach. In the mouth it is mixed with a considerable quantity of the liquid called saliva, and in the stomach with another called the gastric juice, with which that organ always abounds. From the stomach it passes into the intestines, where it is mixed with other two fluids; one called the pancreatic juice, the other the bile. This last is of a yellow colour, and is sometimes produced in enormous quantities, insomuch that Dr. Wade, in his account of the fevers in Bengal, mentions some patients who have voided by stool half a gallon of bilious matter in one day.

28. In the stomach principally the aliment undergoes a certain change called digestion, by which it becomes capable of being converted into the substance of the body. Much has been inquired and disputed, to no purpose, about the nature of this change, and how it is effected. One party has declared for attrition; a second for putrefaction; a third for heat; a fourth have supposed that our meat was digested by chewing; as if, like the lobster, people had teeth in their stomach! and, lastly, some learned moderns, after much pains and trouble, have found out that it is digested by solution. Dr. Moore has summed up the discoveries concerning digestion in the following words: “The food, being previously divided and blended with the saliva and air by mastication, (chewing) is swallowed, and meets in the stomach with the gastric juice, whose dissolving power, assisted by the natural heat of the place, is the principal agent in digestion. The process is completed by the pancreatic juice and bile, the nutritious parts of the food being by this process converted into chyle for the support of the body, and the grosser parts thrown out.”53

29. The inside of the stomach and intestines are full of the mouths of innumerable small vessels, which continually suck up from the aliment, as it passes downwards, the finer parts, in form of a white liquid, called chyle; and from the whiteness of their colour the vessels have the name of lacteals, from the Latin word lac, milk. After passing through the substance of the stomach and intestines, and running along the membrane called the mesentery, to which the intestines are attached, the lacteals unite in a large reservoir called the thoracic duct; and this again opens into a large vein on the left side, called the subclavian, which conveys the blood from half the upper part of the body; soon after terminating in the vena cava, by which the chyle is conveyed to the heart, thence to the lungs, and so on in the common course of circulation. The conversion of the chyle into blood is called the process of sanguification.

30. The blood, thus formed out of the aliment we swallow, is not one uniform fluid like water, but composed of three distinct substances; one, which gives it the red colour, and seems to be composed of little round globules; another, quite colourless, but of a viscid nature, and which very soon coagulates, called the lymph; and a third, of a yellowish colour, and retaining its fluidity much longer, called the serum. A remarkable property of this last fluid is, that air can act through it upon the blood; for Dr. Priestly found that a portion of black blood assumed a bright, florid colour from the air, even though covered with serum an inch deep. When blood is drawn, the red globules are detained by the lymph which coagulates, and both together form the red mass called crassamentum; the serum remaining fluid, and retaining its name.

31. Besides these fluids, the blood either invisibly contains, or is capable of being converted into, a great many others; for all the fluids in the body are separated from it, and all of them, the bile only excepted, from the arterial blood, before it has lost that portion of its spirit which it imbibes from the air. When a fluid is to be secreted, sometimes it is done only by an infinity of small vessels branching off from the arteries, and depositing the liquids which pass through them in particular places; and such are the fluids which moisten the inside of the body, and which are carried off by the breath, or by sweat. But this separation does not by any means hinder the artery from terminating in its usual way in a vein, for in no case is the whole substance of the blood converted into any other liquid; all of them appear to be contained in it. But the greatest number of fluids are separated by means of certain substances called glands. These are small round or oval shaped bodies; each of them enclosed in a membrane or skin which separates it from the other parts, and each furnished with a small tube called the excretory duct, through which the liquor separated in the gland passes to its place of destination. Each gland has also an artery and nerve, and a vein to bring back the blood after it has parted with the fluid intended to be separated. The bile is separated in the liver from the blood of a large vein called the vena portarum, formed by the union of some of the veins of the intestines and mesentery. This vein branches out through the liver like an artery, terminating in other veins, which at last bring back the blood to the heart.