"There is still another principle bearing resemblance to contagion, and affecting the health of masses or bodies of men, of which, as it acts upon the fluctuating bases of moral and mental agencies, it is difficult to give any intelligible account. The health of a ship's company, for instance, or a corps of troops, when the morale is good, the discipline strict but kind, and the confidence of the men assured, will often be found firm in the midst of endemic and epidemie diseases; and plague and pestilence seem to pass them harmless until the introduction of unseasoned recruits, even though healthy at the time,-change of system, or some other cause, makes a break into the general health; and then will the whole rush into disease with a proclivity of current fully as remarkable as the preceding immunity. It would be ridiculous to say that this can be similar to what we often witness in Chorea Santi Viti, or the imitative hysteria of girls, or the familiar acts of yawning, stuttering, &c. Yet it may be akin in a certain sense; since all our sympathies are contagious, as the word itself implies; and when the protecting shield has been removed, these seize the reins, and guide the man without restraint. So fully, indeed, do they possess him, that when his mind is impressed with the dread of impending pestilence, his ordinary diseases, it is well known, will be suspended, and, when it actually arrives, will be merged into the vortex of the new epidemic." P. 178.

There is much good sense and practical value in the following observa. tions on the proper method of arresting the diffusion of typhus, and other contingently contagious diseases :

"Could we establish the point, that this febrile contagion, unlike the poisonous leaven of the variolous fluid, or the venomous fluid of the viper's tooth, which on the reception of a particle contaminates the whole mass, is an infection of accumulation and quantity alone, we shall have attained a degree of security of nearly equal importance to mankind as the discovery of inoculation, or the vaccine preventive itself; for then, instead of man constantly generating a poison which would eventually be fatal to his race, the typhoid virus, without any great stretch of fancy, may almost be taken for the monitor of his life, and preserver of his existence in its due integrity; because that accumulation and quantity, to the degree that can constitute a contagion, being incompatible with the wholesome decencies of life, ought to find no toleration in civilized communities, and may always be obviated by the simplest precautions of domestic police. When these are neglected, the powers of mind and body bestowed by the Creator languish, and are deteriorated, like unhealthy plants deprived of their nourishment in a deficient soil, or of the air and light necessary to their well being; for it has been wisely ordained, that man shall use his faculties to uphold and improve the station that has been assigned to him; and the behests of Providence can never be despised without incurring the appropriate penalty in the diseases that afflict him, and the various plagues that beset his life. It will be vain for him, and his rulers more especially, to plead contagion as a predicament from which they could not escape; for that very contagion is part of their fault, being nine times in ten the work of their own creation, through default of humanity, and in consequence of their crimes. Wherever good government prevails the worst contagion that ever appalled an hospital may be dissipated by the simple separation of the inmates; and the most saturated lazar that ever came out of a pest-house may be disinfected in the burning of a basket of charcoal, putting to flight at once by this simple process the ill-omened hosts of quarantine throughout every nation, with all their vexatious machinery of imprisonment, fumigation, and delay." P. 181. We pass on to consider what Dr. Fergusson says respecting

THE YELLOW FEVER.

It rarely affects the Creolised white inhabitants of the West Indies, and he coloured classes never. How is this?-asks our author. Import

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IS YELLOW FEVER CONTAGIOUS ?

231

among them small-pox, or any truly and essentially contagious disease, and they will suffer even more than Europeans. Take them to England, and they are as liable as ourselves to be affected with typhus. The truth is, that yellow fever "is a seasoning fever of malignant type, the product of high temperature, and unwholesome locality alone."* As a matter of course, the residents are not so much affected by those influences as newcomers from a temperate climate. To show how little contagion has to do with the diffusion of yellow fever, Dr. F. asserts, as the result of his own experience, that the medical men are not usually more liable to its attacks than the other officers of a regiment, and that the orderlies and immediate attendants upon the sick in hospital-provided always this be situated in a healthy locality and be kept cool, clean, and well ventilated-invariably suffer less than the soldiers in barracks. The reason is pretty obvious: the former are not so much exposed to the sun during the day and the dews that fall at night, nor yet to the chances of drunkenness and other mischievous excesses. Again, a vessel, while at anchor in one of the West India ports, may be daily losing some of her crew from yellow fever. No sooner does she set sail, and get a little to the northward, than all trace of the disease usually ceases. As for the alleged transportation of the pestilence from the West Indies to Gibraltar, Cadiz, or any other European port (where it has been known to prevail,) the idea is, in our author's opinion, utterly untenable. These places may produce, or be visited by, the very same malarious influences which gave rise to the fever in the New World. As the typhus of our own country cannot be transported to the West Indies, so the endemic of the latter cannot be transported to, or at least established among, us. A tropical climate is necessary to its existence. These remarks of our author, we need scarcely say, must be received with a good deal of qualification. We shall see immediately how far the history of the "Eclair" fever tallies with some of them. Is Yellow Fever merely an aggravated form of the Remittent Fever of most tropical countries? or is it primarily and essentially a different disease? Dr. F. frankly admits that he is unable to decide the question. There are several circumstances connected with the history of the former-more especially the fact of its unexpected outbreaks in particular seasons which exhibit no appreciable peculiarities, and its equally inexplicable subsequent lulls, while the invasions and departure of the latter are annual and can be calculated with something like certainty; not to mention also the singular circumstance of the black-vomit fever being confined to the African coast and the West Indies, and scarcely if at all known in the East-which must make the cautious enquirer pause before he takes upon himself to pronounce a positive opinion. In considering this question, it should not be forgotten that we are often very much puzzled to account for the exceeding malignancy of certain epidemics of scarlatina, measles, puerperal fever, erysipelas and so forth; while, in other seasons, these diseases, though still

* This definition may fairly be objected to; but we are to remember that the present work is a posthumous publication, and we must not therefore look for the same accuracy and precision of expression that would have been expected, had it been otherwise. Dr. F. himself subsequently disclaims the opinion that yellow fever is merely a seasoning fever.

existing, are comparatively mild and innocuous. To add to the difficulty of solving the problem, Dr. Fergusson states that the Yellow and the Remittent fever often prevail at the same time, running side-by-side of each other. But, whether we regard them to be identical or not, one point has been clearly ascertained, that there is no contagion whatever apper. taining either to the one or the other." The following passage is valuable, from the interesting illustration that is adduced :—

"No experienced men, unblinded by the prejudices of the schools and authorities, or biassed by the expectation of quarantine office, can seriously believe it (yellow fever) to be a contagion. It is a terrestrial poison which high atmospheric heat generates amongst the newly arrived, and without that heat it cannot exist; but it affects no one from proximity to the diseased, and cannot be conveyed to any low temperature. This was finely exemplified at Port au Prince, St. Domingo, where I spent the earlier months of the year 1796. Our headquarters were the town and its adjunct, Brizzoton, as pestiferous as any in the world, and there we had constant yellow fever in all its fury. At the distance of a mile or two, on the ascent up the country, stood our first post of Torgean, where the yellow fever appeared to break off into a milder type of remittent. Higher up was the post of Grenier, where concentrated remittent was rare, and milder intermittent, with dysentery, the prevalent form of disease; and higher still was Fourmier, where remittent was unknown, intermittent uncommon, but phagedenic ulcers so frequent as to constitute a most formidable type of disease; and higher still were the mountains above L'Arkahaye, of greater elevation than any of them, far off, but within sight, low down in what was called the bight of Leogane, where a British detachment had always enjoyed absolute European health, only it might be called better, because the climate was more equable than in the higher latitudes. Here were the separate regions or zones of intertropical health mapped out to our view as distinctly as if it had been done by the draughtsman. Taking Port au Prince for the point of departure, the three first could be traversed in the course of a morning's ride. We could pass from the one to the other, and, with a thermometer, might have accurately noted the locale of disease, according to the descending scale, without asking a question amongst the troops who held the posts: and what kind of contagion must that be, which, amongst men in necessary intercommunication, eannot be conveyed from the one to the other, which refuses to mingle with another of lower temperature, although within sight, and so near, topographically speaking, as almost to touch? The men could, and did, constantly exchange duties, but not diseases; and it was just as impossible, and more so, to carry a yellow fever up the hill to the post in sight, as it would have been to escape had they been brought down and located amidst the swamps of Port au Prince. These things were known to every person in the army, whether medical, civilian, or military, and amongst them all there was not to be found a single person who had the smallest belief in contagion, provided always he had been a year in the country, and possessed opportunity of seeing with his own eyes,-all, I may say, came out contagionists, myself amongst the number, none remained so." P. 153.

Dr. Fergusson adduces a variety of considerations to show that Yellow Fever is never essentially and intrinsically contagious. That it may ac quire contagious properties, when the air, in which it was first developed, becomes vitiated with emanations from the sick, is highly probable: but this is an adventitious, not a necessary, property of the disease. The very exemption of the negroes from its morbific influence is a strong argument in favour of its being not contagious at first. Then, again, it is limited, in a great measure, to particular localities, temperatures, and elevations

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OPINIONS OF RECENT WRITERS.

233

"Places,

a character not very consistent with essential contagiousness. not persons," constitute the rule of its existence. It prevails during the highest tropical heat-the very condition that usually arrests the progress of infectious fevers, such as the plague (which usually ceases on the advent of Midsummer) and typhus.

In reference to the proper means to be taken to mitigate and arrest the pestilence, Dr. F. most justly remarks:

:

"To pen up the inhabitants upon the infected ground is to aggravate the disease a thousand-fold, and is, in fact, as cruel and absurd as it would be to barricade the doors against the escape of the inmates of a house that had taken fire, on the insane pretence that they would otherwise spread the conflagration. The quarantine authorities will no doubt interpose to save the world from the dire contagion: but let them be referred to the annual epidemic at New Orleans for information how often the yellow fever has been conveyed from thence to the upper settlements on the same river, to which the fugitives, sick and well, uniformly fly for refuge, or even to the steamers that carried them; how often at Vera Cruz it has been carried out of the town even to the first stage on the road into the interior; or how often in Spain it has ever been transported, except to another station under the same circumstances, of heat and drought and defective perflation, therefore falling, if not having already fallen, into the same predica-! ment from the same causes. Let them inquire whether seclusion and shutting up has ever saved the terror-struck. In the army of St. Domingo it was notorious that they were ever the first to be taken ill, and the surest to die; and during the yellow fever epidemic of 1816, at Barbadoes, I have recorded remarkable instances of the same both from my own observation and that of others. In short, whenever the endemic agency could not be avoided, the best place of safety was often to be found in the sick apartment, for there quietude reigned, and fatigue, exposure, and intemperance, were most likely to be avoided." P. 158.

Drs. Bone, father and son, are as decided anti-contagionists as Dr. Fergusson; and, as the former has had a long and most extensive acquaintance with the diseases of the West Indies, his testimony must carry very considerable weight. We may quote the following passage from the inaugural dissertation of his son upon this point :

"In hospitals that are well constructed, and where a correct hospital discipline is enforced, the attendants of yellow fever patients are not liable to the disease. "The Naval Hospital, Barbados, was built by Admiral Cochrane, and was well constructed; each orderly employed in the wards had a sleeping-room partitioned off from the ward. The sick of the Pyramus frigate and of detachments were treated in that hospital in 1821 and 1822. The total number of persons treated in the hospital from 21st of June, 1821, to 22d February, 1822, was 243. Of these, 101 were fever patients, and 38 were convalescents from fever. None of the patients under treatment for other diseases caught yellow fever; none of the servants, 38 in number, or of the other persons employed in the hospital, 53 in number, were affected with yellow fever. Twenty-two persons died of yellow_fever, and were all, except one or two, carefully examined after death by Dr. Bone or by his assistants, Dr. Bain and Mr. Campbell, and none of them caught yellow fever.

"But is there any danger in entering an hospital where there are patients with yellow fever? Yes, if that hospital be filthy, crowded, ill-ventilated, and the patients lying on the bedding they have soiled: for the air must be vitiated, deprived of its oxygen, charged with azote, and other pernicicus gases, and therefore unfit for respiration; and the sight is shocking and the groans of the dying frightful; but were the patients affected with any other disease, or, on admission

with no disease, and similarly circumstanced, the danger from breathing the vitiated air among them would be equal." P. 21.

Both Dr. Bone and Dr. Fergusson expressly assert that the disease is apt to be generated on board ship, in tropical climates, from an impure state of the hold. The latter, alluding to the cases of the Regalia transport from the coast of Africa, and of the Childers sloop of war-of which he has given an account in the 8th volume of the Medico-Chirurgical Transactions-assures us that, whenever the holds of these vessels were cleaned and purified, the fever ceased. "Before that was done, whatever stranger slept in either of them for a single night, was assuredly taken ill; whoever was brought sick ashore into the fully occupied wards of our general hospital, and received with open arms, brought with him as little infection as the new-born babe."*

We may point to the testimony of Mr. Birtwhistle also, late surgeon of H.M.S." Volage," as given in a recent number of the Lancet (3d Jan. 1846.) In the Spring of 1342, yellow fever having broken out in this vessel at Port Royal, she was ordered by the commodore on the station to proceed at once to Halifax. For some time after her departure from Jamaica, the disease prevailed, and indeed with increased violence, on board; for fresh cases continued to be added to the list even for some time after the ship's arrival at Halifax, and did not completely cease until all hands were landed on Navy Island. Let us now see what opinion Mr. B. formed as to the producing causes of the fever, and consequently as to the best means of arresting its diffusion.

"After maturely reflecting on the origin, progress and termination of this dreadful malady in the Volage,' and weighing well everything which could in any way tend to produce or aggravate it, I must confess that it is difficult to come to a perfectly satisfactory conclusion; but it is, I think, evident that the primary cause was our lengthened stay at Chagres, Carthagena, and Santa Martha, where the fever first seriously presented itself, and where all the sources of malaria are most abundant; and that the manner in which it subsequently raged amongst the crew, first attacking the officers and servants residing in the steerage and after-part of the vessel, and thence proceeding to the adjoining mess of the marines, only one of whom escaped, and afterwards, forwards to the seamen, clearly indicate that in the vicinity of the pump-well there was some fatal miasma arising, which could not be, and was not removed until the thorough cleaning, drying, whitewashing, and fumigating, which she received at Halifax, all the stores and tanks being taken out for the purpose, and the holds being kept empty for nearly a fortnight. I had the gratification to find that the removal to the shore, and cutting off, for a time, all communication with the vessel, proved a most effectual remedy, inasmuch as from that period I had not a single new case, and the sick regained their strength in a rapid and surprising manner.

He adds:

* We need scarcely say that Dr. Fergusson rejects the idea of Cholera being a contagious disease: "always however with the proviso and exception of the possibility of its being made a temporary contingent contagion amidst filth and poverty, and impurity of atmosphere from overcrowding and accumulation of sick, but neither transmissible nor transportable out of its own locality through human intercourse."