“Docebo causas, quas diligentiâ experientiâque comperi.”

Experience has taught us that the phenomena of epidemic pestilences or diseases are various and dissimilar, observing no regular course or succession, but commencing and ceasing at periods influenced by certain changes of the seasons, and modified by various circumstances, especially such as locality and habit of body.

The chronicles of all nations are replete with notices respecting the remarkable commotions of nature, which have proved from time to time so inimical both to the animal and the vegetable kingdoms; and on carefully reviewing the facts detailed in the histories of epidemic pestilences or diseases, it will be readily perceived that, during certain periods or seasons, ELEMENTAL DISTURBANCE has enveloped, as it were, the entire globe, carrying death and misery into every quarter. I am, therefore, of opinion that the grand phenomena of nature, exhibited in the commotions of our physical world, supply us with abundant materials for the explication of all epidemic pestilences or diseases; that the latter are consequently assignable to natural causes, without searching for or hunting after mysterious agencies, to the neglect of those which Nature is constantly presenting to our view.

I am fully aware that ascertaining the causes of maladies of any description is a matter attended with much difficulty, not only from the variety and impalpable nature of the causes themselves, but also from the peculiar functions and various idiosyncrasies of the living system on which such causes act; numerous conditions being found capable of modifying the effects of a common cause of disease, viz. the season of the year, peculiar state of the atmosphere, especially as regards heat and humidity, circumstances of locality, the different temperaments of individuals exposed to their agency, the influence of previous ailments,—all these concurring more or less in the production of diversified forms of disease.

By way of illustration and with reference to atmospheric influence—the grand exciting cause of disease,—every practitioner is familiar with certain conditions which are favourable to the production of certain disorders, such as common catarrh or cold, and its more aggravated form termed influenza,—hooping-cough, bowel affections, gastric fevers, &c. The effects of external temperature first produce on the functions of the skin (which connects us with the exterior world) an augmentation or diminution of the natural discharges, by suddenly changing or disturbing the balance of the circulating fluids between the external and internal parts or surfaces, irrespective of the perspiratory process, commonly termed sweat, there being innumerable chemical agents more poisonous and of greater importance as to their elimination from the system in the shape of insensible perspiration. I repeat, that the effects of external temperature, by causing a repercussion of the cutaneous exhalations (sensible and insensible), so damage the vitality of the system, as to be the exciting cause of disease; and, although from our imperfect knowledge, it scarcely admits of investigation, setting aside chemical research, so that we cannot explain or define the precise peculiarity of each and every condition of the atmosphere favourable to the production of each variety of disorder, the effects of such external temperature are, however, not the less certain and obvious to our senses. The agencies are all natural, comprised in the excess of state or change acting on individuals whose susceptibility varies greatly from moral as well as from physical predisposing causes; but our inability to define their peculiar conditions or auræ, as noticed by Hippocrates, Sydenham, Bacon, and others, no more militates against our reasoning upon their visible effects, than a knowledge of the gravitating principle or power is essential to the proof of gravity.

But to the subject of the causes,—the exciting and the predisposing of disease; it should be premised that when attributing epidemic pestilences or diseases to natural causes, it must not be supposed or inferred that any one of such causes, as heat, cold, moisture, drought, &c., will alone be sufficient to induce disease: to effect that, there must be a combination of these causes in continuance and succession, in occasion and variation, as also in circumstance and virulence.

It has always appeared to me that a proper and sufficient distinction is never, or rather, has never, been made, between the predisposing and the exciting causes of disease—an error which leads to much confusion and to contradictory conclusions on all sides. Par exemple, in a Report on the epidemic pestilence which raged some years ago in Ireland, it was unanimously determined, (so says the Report,) “that the predisposing causes were, rapid atmospherical vicissitude, low marsh and other effluvia.” Here we have the exciting cause, ‘atmospheric vicissitude,’ jumbled together with a predisposing cause, ‘marsh effluvia;’ while on the other hand, in recent Reports on cholera from various authorities, we have marsh and other effluvia assigned as the exciting causes, which, on reflection, will strike any one as being obviously fallacious, inasmuch as if marsh and other effluvia are to be considered as exciting causes, instead of predisposing to disease, we should scarcely ever find those places free from pestilence where these matters are supposed to be engendered, whereas we see various localities in South America,—in British Guiana, for instance, and even in Ethiopia,—which have been condemned as the hot-bed and nursery of pestilence, where putrefaction is supposed to concoct and concentrate its most lethal poisons,—still enjoy their seasons of salubrity: it is, I repeat, from the absence of such distinctions as to the exciting and the predisposing causes, coupled with the non-consideration of the great variety of circumstances, both past and present, local and general, individual and common, which are influential in the production of disease, that so much uncertainty and disputation as to the causes of epidemic pestilences have arisen. Such distinctions will appear to be more important and necessary for the prevention and mitigation of epidemic pestilence or disease, when properly considered, inasmuch as the predisposing causes, which are in a great degree under our control, are always in existence or operation to a greater or less extent, while the exciting causes may be said to be of only occasional occurrence.

As before observed, the causes of diseases are described as the predisposing and the exciting. The former, the predisposing causes, I understand to be,—the want of light; impure air (especially from defective ventilation), in which are included malaria and all other noxious vapours, from whatever source arising; a scanty and impoverishing diet; and, though last, not least, habit of body, induced by the irregular and artificial life of man in a state of civilization, which, by enervating the system, induces the predisposition to disease by rendering the human frame more susceptible to external impressions; the grand excitants of disease, such as elemental disturbance, consisting of variations of temperature and the state of the surrounding medium, as to hygrometric influence, electrical tension, &c.

Naturalists in all ages have concurred in the opinion that sudden atmospheric mutations act injuriously on the subjects of the vegetable kingdom as well as on those of the animal, and it will, I presume, be admitted that the existence of the vegetable kingdom is necessary for the support of the animal,—the physiology of both reflecting much light on each other. We see the vegetable kingdom assailed by disease termed blight,—‘pestiferous blight,’ as it has been called by some; these blights are but pestilences affecting the vegetable kingdom, and have ever been attributed to natural causes, elemental disturbance, &c.

At the periods which have been remarkable for the occurrence of blights, animals—such as horned cattle—have been known to suffer sooner or later; and man also, as I shall in the course of these pages fully show. Reasoning analogically, therefore, may we not conclude that that state or condition of the elements which induces blights,—pestilences in the vegetable,—will also act injuriously on the animal kingdom, more especially on the human race, men being, from habit of body, &c., more prone to or susceptible of disease?

Referring to the annals of history, which so abundantly show that the ancients considered all universal distempers as originating in the disturbed states of the seasons, I will cite a few instances (commencing with sacred history) explanatory of the causes of universal maladies, termed epidemic pestilences or diseases.

In the books of the Old and New Testaments we find beautifully described the great causes of pestilence inducing their effects in regular succession and with absolute certainty. The books of God, in tracing the hand of Omnipotence through the medium of secondary causes, producing effects punitive of guilty mortals, attribute all diseases to the immediate interposition of Divine Providence:

“Pestis et ira Deûm Stygiis sese extulit undis.”

And why?—Because God is the first great cause, the original creator of all things, the preserver and governor of all things in heaven and on the earth, and likewise the sole disposer of the elements.

Seeing, therefore, that our Creator, while possessing the sovereignty of the universe, may employ what agents he pleases for the execution of his purposes, we, in investigating the causes of all distempers, without in the slightest degree impugning their divine origin, can perceive that the Almighty Disposer of events effected his purposes by the employment of natural means;—further, in expounding the causes of disease, as existing in natural and common things, and modification of beings and things of this natural world, we can do equal homage to the Almighty’s wisdom and goodness, omnipotence, justice, mercy, judgment, and providence, as we can in displaying them as immediately inflicted on guilty man. Yea, more glorious do the attributes of the Most High appear in the sublime mysteries of nature!

To particularize: when the governors of the five cities, Gath, Ekron, Askelon, Gaza, and Ashdod, met for the purpose of contriving to rid themselves of the ark which the Philistines had captured from the Hebrews, it would appear that they were cognizant of the natural means adopted by the Almighty to effect his purposes, although they, in their impiety, doubted the divine origin of their affliction by pestilence. Overlooking the omnipotence and all-wise direction of their Creator, they exhorted the people to bear patiently that which had befallen them, and to believe in no other causes of the pestilence which was effecting their destruction than those springing from the operations of nature, which at certain revolutions of time produce such mutations in the bodies of men, in the earth, in plants, and in all things grown out of the earth, as to excite disease.

With reference to elemental disturbance, the prophet Amos (ch. iv. vss. 8 and 9) first describes the occurrence of a great drought, then the generation of insects—the palmer-worm and the canker-worm, which destroyed all foliage and herbage: vegetables, orchards, and olive-yards, all fell a sacrifice, and induced a grievous famine, succeeded by a dire pestilence.

Habakkuk, in his prayer, (chap. iii.) makes allusion to a great pestilence preceded by earthquakes and great commotions of the elements; the sun and moon standing still in their habitations, the mountains trembling, and the waters overflowing, causing famine and pestilence, to the destruction of 14,000 persons.

Again, in the 28th chapter of Deuteronomy, which contains the promised cursings and blessings of the Almighty on his people, we have a proverbial figure of speech, expressively illustrative of the natural means employed by our Creator in effecting his purposes: “And thy heaven shall be brass, and the earth iron;” the one denoting a drought, during which the heavens will yield no rain, inferring also extreme heat; the other, the unproductiveness of the earth, yielding no fruit,—the effects of such drought being to induce famine, and ultimately disease. The experience of our own times exemplifies in the fullest manner the concurrence, from physical causes, of famine with pestilence—facts which the prophets of old always connected, viz., the sword, famine, and pestilence, as being three evils which generally accompanied or followed each other; and we cannot conceive a doubt as to the association not being accidental, especially of the two latter, but arising from their dependence upon similar atmospheric phenomena.

Jeremiah (chap, iv., vss. 11 and 13), in describing the approach of the armies of Babylon, compares them to the drying, parching, scorching, and blasting winds of Egypt, Africa, Arabia, and Asia, which wither and destroy the fruit of the earth, melting and oppressing all living creatures; and he likens them to clouds of dust and whirlwinds traversing those pestiferous countries of the East, where the heat and drought, the dews and damps, heavy rains, the cold north winds of winter and spring, succeeded by the suffocating heats of summer and autumn, generate pestilence and cutaneous diseases.

In turning to the history of Egypt,—to this day a hot-bed of pestilence,—we have graphically pictured a series of events occurring and ending in the production of pestilential disease. The waters of the rivers were first turned red, the fish died, and stank therein, causing putrefaction of their bodies, while the waters became unfit for use, either by men or beasts: secondly, swarms of frogs infected the land, penetrating into the very houses; these were succeeded by a host of insects, lice, flies, &c.: thirdly, the beasts of the field suffered from murrain; and finally, man suffered from boils, blains, &c. If we look into the topography of Egypt, we shall find abundant causes to account for its great and continued insalubrity;—the whole country lies near the tropic of Cancer; it is bounded towards the east by the Red Sea, on the west by the deserts of Libya, on the north by the Mediterranean, and on the south by Abyssinia or Upper Ethiopia. All the lower country is encompassed by the arms of the Nile, and is inundated annually by that father of rivers, when it overflows: it rises twenty-four feet in perpendicular height at the medium increase of four inches daily, and it continues from the end of June to the beginning of September, when it begins gradually to subside. The inhabitants sow their corn and vegetables in October and November, immediately after the retiring of the waters; their harvest-time is in March and April. Volney observes that the surface of the land successively assumes the appearance of an ocean of fresh water, of a miry morass, of a green level plain, and of a parched desert of sand and dust, and all in such rapid succession that it can never be otherwise than insalubrious.

To recapitulate more fully. In that calamitous period in the days of Moses, as shown in the history of Egypt already alluded to, the season was distinguished by an extraordinary phenomenon, the waters being turned to the colour of blood by the addition of some remarkable materials or insects which killed all their fish, and caused the waters to stink in all the low lands of Egypt, so that they could not drink the waters of the river or of their ponds for seven days; this peculiar condition of the waters, and the heat of the atmosphere, engendered swarms of frogs, which, it is stated, came up into their houses, into their very bed-rooms, entered into their ovens, and even into their dough. Some great commotion of the elements, or a great and sudden change of the weather, killed the frogs in their houses, villages, and fields. When the people gathered their carcases into heaps, so great were their numbers that the whole land stank with their putrefying bodies; lice began afterwards to infect the inhabitants, as well as the bodies of domestic animals; swarms of noisome insects, such as flies, &c., succeeded the general putrefaction of the dead frogs, and as the excesses of the seasons continued and increased, a mortal pestilence among domestic animals, cattle and horses, camels, oxen and sheep, ensued. This was the presage to an awful pestilence among men, according to the common course of nature; indeed the Egyptians had not recovered the loss of their cattle, when fiery pustules, apostemes, and putrid ulcers infested their own bodies. After this succession of evils, a dreadful storm of hail arose and destroyed cattle, herbs, and fruit; in this tremendous tempest, we read that the lightning, mingled with hail, ran along the ground, and was so very dismal and grievous in its appearance and effects, that Pharaoh and all his people trembled as if the pillars of nature had been shaken to their very foundation, and the world was about to come to an end: to add to these dire calamities, hosts of locusts were brought by the east wind over all the land of Egypt; they rested on all the coasts and borders of the land, covering the face of the earth, so that the ground was blackened by them; while they devoured the residue of the herbs which the hailstorm had spared, not one green thing remaining in the land of Egypt.

Soon after this, a strong west wind began to blow, which cast all the locusts into the Red Sea, where they were drowned; their bodies being subsequently washed on shore, stank intolerably, and became a great auxiliary cause of pestilence amongst the inhabitants. Meantime three days of astonishing darkness spread over all the land, and the inhabitants could not see each other, neither did they rise from their seats; pestilence meanwhile was rife in the land. This terrible distemper first seized all the young and robust, all the first-born of man and beast—from the first-born of the king to that of the slave,—yea, there was not a house in which there were not some dead; so tremendous was the stroke that the sacred historian calls it the immediate judgment of God to punish their wickedness. And behold it happened in the dead of the night, says the devout narrator, that the Lord smote all the first-born of Egypt, from the first-born of Pharaoh that sat on the throne to the first-born of the maid-servant that stands behind the mill, and even the firstlings of the beasts;—in short, so dreadful was the calamity and destruction that the Egyptians cried out, “We be all dead men!”

Looking to all the foregoing circumstances detailed, can we hesitate to attribute the terrible malady which prevailed in Egypt to any but the pestilential constitution of the season?—can we suppose the operation of any other than natural causes, such as long drought, excessive heats, hot burning winds, clouds of suffocating dust and sand; heavy rains succeeding the drought; storms of hail mingled with lightning; famine, the consequence of the destruction produced by the locusts and devouring insects; the noxious emanations from dead frogs which had been destroyed by the dismal commotions of the elements; and the insufferable stench arising from the carcases of the quantity of dead animals? Can we imagine, I ask, any other causes to have been in existence to produce such awful pestilence than those of the sudden great changes of the weather, inundations of the rivers, and the universal corruption of dead animal and vegetable matter throughout the dominion of Egypt? I reiterate the question,—have we not abundance of material to account for this terrible infliction on the people of Egypt?

About this period of dire suffering of the Egyptians from pestilence, the first dreadful epoch of Spanish epidemiology is recorded as having commenced; the date, however, has been variously given. By some writers it is fixed about the time of David, 1017 B.C., when 70,000 persons were destroyed in three days by pestilence; by other writers it is stated to have commenced amongst the Spanish 1100 B.C. There were twenty-five years of drought in Spain without interruption; springs were dried up; rivers became fordable, their waters being almost stagnant; there was neither pasture for beasts, nor fruit for man; so great was the barrenness of the land, that there was scarcely anything green to be found, except some few olive-trees on the banks of the Ebro and the Guadalquivir: such, says the historian, was the melancholy state of ancient Spain, “full of dreadful mortalities, plagues, and miseries of every description, which, with emigration to other lands, nearly depopulated our country.”

The Greek poet, Homer, describes the causes of the pestilence which attacked the armies at the siege of Troy as being attributable to the extreme heat of the weather and the unfriendly seasons. He styles the sun Apollo:

Thucydides, another celebrated Greek historian, describes a similar condition of the atmosphere with physical irregularities, as causing an awful pestilence at Athens:

Lucretius, in imitating Thucydides, thus expresses himself:

The poet Ovid, in the seventh book of his Metamorphoses, in describing the terrible pestilence which occurred in the island of Egina (see ‘History of Pestilences’), represents the pestilence as arising from the following causes:—He exhibits the earth covered with dense clouds, darkness, and suffocating heat; the deadly south winds blowing for four months, the very vapours of disease; the lakes and fountains infected, the air poisoned, and the entire land infested with venomous serpents, as happened to the people of old. The plague or pestilence first attacked horses, oxen, mules, sheep, dogs, cats, and even birds, and then it affected mankind; death was sudden, and the streets were choked with the carcases of men and beasts, and universal nature seemed to be suffering from premature caducity.

In order to show the identity of this pestilence with the plague of Egypt, the bilious remittent or yellow pestilence of the West Indies and the United States, the disease termed Andalusian fever which has from the earliest ages made such havoc in Spain and the adjoining country, and also with the pestilence which has more than once visited both England and Ireland in days of yore, we have collected the symptoms of that disease from Ovid’s poetical enumeration of the morbid phenomena, which were,—great heat in the bowels, flushings of the face, difficulty of breathing, bilious vomiting, pains in the head, with obstinate constipation, great prostration of strength, unquenchable thirst, delirium, often attended with coma, great anguish, dry black tongue, cough, &c., which proceeded to a fatal termination in the course of two, three, or four days: the following is a translation or imitation of the original.

Hippocrates, the great founder and parent of rational medicine, in his book on Epidemic Distempers, accurately delineates the vicissitudes of the weather and the different seasons of the year, attributing to them the causes of all diseases. He thus describes a state of atmosphere producing a most extraordinarily dismal pestilence and mortality: A season marked by abundant showers, a south wind following drought; a hot and sultry autumn, with abundant rain; a humid, open, light, and warm winter, extremes of cold after the conversion of the sun under the equinox, with winds blowing, with snow and sudden great change of weather.

“Annus austrinus, imbribus abundans atque in totum ventis tranquillus fuit. Quum autem paulo superioribus anni temporibus justo majores siccitates viguissent, sub Arcturum sperantibus austris multum fuit. Autumnus obscurus, nebulosus, cum aquarum abundantiâ, hyems austrina humida et levis. Longo vero post solis conversionem intervallo juxta Æquinoctium, extremæ hyemes adfuerunt; jamque sub Æquinoctium ipsum Aquilonares venti cum nivibus non ita diu speravere. Ver rursus austrinum a flatibus quietum, aquæ multæ et continentes ad canem usque. Æstas verum calida, æstus præfocantes magna. Anniversarii venti (Etesias vocant) pauci disjunctim speravere. Sub Arcturum rursus spirantibus aquilonibus aquæ multæ.”—(On Epidemics, bk. iii. sect. 3.)

Again, in section 8 and 18 we have: “In aëre considerandum quanta insit caliditas, frigiditas, crassitudo, tenuitas, siccitas, humiditas an plenior an vero minor et copiosior. In quibus quænam mutationes et ex quibus fiunt, quomodoque se habeant, animadvertere oportet,”—plainly signifying that a pestilential constitution of the seasons consists of atmospheric vicissitudes, heat and cold, dryness and moisture out of season and in excess.

Galen, the great commentator on the works of his master, assigns two causes to pestilence; the one, a great irregularity of the seasons, and consequently a pestilential state of the air; the other, a vitiated condition of the human body from corrupt and defective food, impure air, &c., by which means it is rendered liable to disease: here we have the exciting and the predisposing causes of disease clearly pointed out.

Further, in illustration of continued drought inducing famine with its other evils, disease and mortality, we may quote Tasso’s beautiful description of the sufferings of the Christian army under the walls of Jerusalem:

The learned prelate Eusebius gives a very philosophical description of the impure state of the atmosphere during a great pestilence which ravaged the Roman empire. He writes thus: “The air was so noxious, every where deranged with corrupt vapours, fumes from the earth so putrid, winds from the sea, exhalations from marshes and rivers so injurious, that a certain poisonous liquor, as it were from putrid carcases, was brought by the elements, and covered the subjacent seats or benches, walls, and sides of houses, and the dew appeared like the sanies of dead bodies.” (See edit. Paris. 1628.)

Tacitus, in his description of Rome, notes the occurrence, every third or fourth year, of what they termed “tempus grave aut annus pestilens,” and he gives the following tetrastichon—

If the site of Rome with its other concomitants be considered, we shall readily understand why pestilences were there so rife. It is situated in a level country on the low banks of the Tiber, surrounded by the extensive Ostiensian and Pontine marshes, exposed to the powerful rays of the sun, and subject to inundations and other commotions of the elements; further the inhabitants having been constantly engaged in war, did not cultivate their lands sufficiently to produce food for half the population, nor had they any established commercial intercourse with other countries, from which they could be supplied in times of scarcity. From their perpetual inroads agriculture was also interrupted among all the adjoining nations, and the far-famed Romans were often reduced to the necessity of feeding upon grass, leaves, and unwholesome roots, or of consuming the provender stored for their cattle, till men and beasts, and, it is said, birds and fish, perished together, so pestilential were the seasons; “vulgato per omne genus animalium morbo.”

I might go on multiplying authorities ad infinitum to show that previously to the middle of the seventeenth century those ages were full of physical and political miseries, sufficient to account for the frequent outbreak of fatal maladies; and we shall also find that subsequently to that period all those countries that have adopted judicious regulations in the construction of their dwellings, in widening their streets, improving the drainage, and securing an adequate supply of the three grand essentials to vitality,—light, air, and water, have proportionately experienced a corresponding immunity from pestilence, a notable exemplification of which we have in this our own country, although we are far, very far, in this the nineteenth century, from the improved condition that our wealth and the repeated warnings of disease which have been vouchsafed us, especially since the year 1832,—now nearly twenty years,—should have given rise to.

It was not, however, until after the great fire in 1666, at the rebuilding of London, as it were, that any measures were taken to secure the public health. In the year 1665, during the time of the great and terrible plague, our streets were narrow, and the houses, which were built of wood, closed inwards towards each other, one story projecting considerably above the other, till they seemed almost to touch each other at the top, and looking upwards from the street towards the sky was very like looking up from the bottom of a well. There were scarcely any sewers; the streets were damp and wet, and nearly everything in the shape of offal was thrown into them, while certain corporate bodies, the ecclesiastical authorities even, contended stoutly for the right of sending their swine into the streets to feed upon such garbage as they found plentifully therein. It would also appear that the general habits of the citizens in no way counteracted the bad effects of their faulty architecture by domestic cleanliness.

The celebrated Erasmus asserts that the interior of the dwellings in London was disgusting to the last degree. He plainly ascribed ‘the sweating sickness,’ which was a species of plague, to the incommodious form and bad position of the houses, the filthiness of the streets, and the sluttishness within doors. In a letter to a physician of Cardinal Wolsey’s, in which he gives an account of the domestic habits of our countrymen in those days, he says, “There is a degree of uncleanliness, and even of filth, pourtrayed, of which we can have no conception in our times.” He continues: “The floors are commonly of clay, strewed with rushes, which were occasionally removed, but underneath lies unmolested an ancient collection of beer, grease, fragments of fish, spittle, the excrements of dogs, cats, and everything that was nasty.” Hentzer observes, that even the floor of the presence-chamber of the Queen Elizabeth, in Greenwich Palace, “was covered with hay after the English fashion;” and Hume remarks, as a proof of the meanness of living in those days, “that the comptroller of the household of Edward the Sixth paid only 30s. a year for his house in Channel Row, which like the generality of the streets of London was unpaved and undrained, and contained an accumulation of the offal and such filth as was habitually thrown into them.”

Sydenham, who writes of the changes produced in the amount of disease according to locality, the constitutions of the seasons, &c., notices that London in his day was ill-built, ill-drained, ill-supplied with water, and the neighbouring country to the very suburbs so badly cleared, as to subject the inhabitants to a return of agues regularly in spring and autumn; and in the journal of De Foe we have assigned as one of the many causes of the pestilence that occurred in this country in 1665, the crowded state of the city and suburbs, which were prodigiously full in consequence of the disbanding of the armies after the restoration of the royal family and of the monarchy. Our city, says De Foe, was computed to have had in it 100,000 inhabitants more than it ever entertained before; some computed the number as being twice as many, so that pestilence became in one year (1665) more terribly destructive from the immense numbers crowded together, aided by peculiar elemental disturbances, which had been rife for several years previously; pestilence indeed may be said to have existed in London continuously from the year 1661 unto 1666.

In the year 1665 the terrible plague became aggravated in the month of July, from the sultriness of the atmosphere, cold nocturnal dews or damp fogs, frequent cold showers and cold winds alternating with the warmth and dryness of the air; in short, every extreme vicissitude seemed to exist in that dismal period of disease and death, producing agues, bilious disorders, bowel complaints, &c. In the next month the great general pestilence appeared to swallow up as it were all previous diseases in one common destruction. Indeed, from the month of August all other diseases were absorbed in the pestilence: all distempers, commencing in their usual form, were uniformly resolved into the deadly plague; and in the month of September, says the great historian, “Death rode triumphant among the devoted inhabitants of London; having borrowed the fatal scythe of Time, he mowed down the people like grass, and immerged the poor remains in horror and despair.”

Having advanced thus much in support of the natural causes of universal distempers or epidemic pestilences, culled from the histories of pestilences from the earliest ages, we arrive at the consideration of that ‘vexata quæstio,’—contagion.