India Islands, and in parts of the American continent, have been much milder than the visitations of this pestilence have been in Spain, during the early part of the present century. But it is by no means fully ascertained whether all the epidemics observed in the western hemisphere were actually the true yellow or hæmagastric fever, or merely an unusual prevalence of endemic or remittent fever, rendered more continued by intensity of attack, predisposition of the affected, and other circumstances. No doubt several of these epidemics were the pestilence under consideration. Their symptoms, remarkable prevalence, and fatality proved that some of them were this distemper; but others were of a different nature; and probably some of them resulted from the crowding of a number of human beings in a confined space, either in barracks, or in transports, or between the lower decks of ships of war, in a high range of temperature, and without sufficient renewal of the air." Vol. III., p. 149. How much it would have tended to elucidate this perplexed subject, if Dr. Copland had specified which of the epidemic visitations, alluded to, he regarded as belonging to the genuine pestilence, and which he looked upon as belonging to other forms of fever! As the matter stands, it is not possible to establish any comparison between the one set and the other, and thus seek to discover their prominent points of difference, if any such really existed in nature. But, without dwelling upon this point, and adverting only to the (supposed) negro origin of the genuine disease, one or two difficulties will immediately suggest themselves to the reader's mind. How comes it that we do not hear of the disease (so, at least, it is asserted by our author) "in the eastern hemisphere, and on the shores of the Pacific?" Have not many crowded slavers arrived, at different times, at the Mauritius and the Isle of Bourbon? and is there not a regular slave trade carried on in the present day at the island of Madagascar, where, nevertheless, the true yellow fever is said never to have been known? Apart, however, from these considerations, is there, we would ask, any other example of an essentially specific disease, a disease sui generis, and proceeding, as it is declared, from a morbific seminium or virus analogous in its nature and peculiarities to that of Small-pox or of Measles (for all this is asserted), being produced by, and originating from, the mere accumulation of human beings under any circumstances? Are any of the Exanthemata ever so developed? or is there any reason to believe that the other two pestilences described by Dr. Copland-viz. Epidemic Cholera and the Plague-ever originate from the cause mentioned, apart from the operation of certain endemic malaria? Again, is it not somewhat surprising that a disease, (supposed to be) generated by negroes, should exert its infectious properties comparatively so exclusively upon the white races of mankind, and more especially upon those who have recently arrived in a tropical region? Is there any analogous instance of such a limitation, on the part of an essentially infectious disease? We surely know of none. Small-pox commits its ravages with equal fatality among all races of the human family, who have not been protected by vaccination; and the same thing may be said of Measles and Scarlet fever. But it is very different with the Yellow fever. The negro races, it is well known, although certainly far from being exempt from its invasion, seldom suffer so severely from it, as those whose systems are less acclimated to the heat and malaria of a pestiferous climate. Does not this circumstance alone point to some connection, in nature as well as in cause, between this and 1847] Is it essentially Infectious? 205 the ardent or seasoning fever? We have already seen how closely a malignant case of the latter resembles, in all its features, the most fatal yellow fever. But passing from these considerations, we should like to be told how the Malignant Remittent, when it assumes a continued type and acquires infectious properties, is to be distinguished from the genuine Pestilential disease. This dangerous modification of the former is apt to take place in certain seasons, when the endemic fever prevails in an epidemic form, and especially when the vital organs and the circulating fluids are more seriously affected than usual. Under such circumstances, it is unquestionably liable, as Dr. Copland allows, to become infectious whenever a number of the sick are crowded together in badly-ventilated places, "during very warm and humid states of the air, so as to contaminate the surrounding atmosphere, and thereby either to superadd the additional cause of a morbid effluvium, exhaled from the sick, to existing marsh miasma, or to generate a morbid poison or vapour which is of itself capable, independently of marshy or other miasmata, of infecting the healthy and disseminating the distemper.” "That a superadded quality," our author goes on to say, "or at least a change of character, should result from the circumstances just alluded to, may be rationally inferred; for the aggravation of symptoms and the development of new features in these altered circumstances have frequently been observed, are undoubted, and are the chief sources of much of the differences of opinion and of the discussions which have appeared, since the end of the last century, on the subject of the Yellow fever." Yet he afterwards, in more passages than one, appears to argue as if the possibility of the endemic fever ever becoming infectious was entirely out of the question. For example, when combating the doctrines of the venerable Jackson on the subject, he writes thus : "He (Dr. J.) remarks that there is not one practitioner in one hundred who has resided for years in the West Indies, who believes that the concentrated endemic of that country, usually called the yellow fever, is a disease which possesses the power of propagating itself from person to person within the tropics.' Certainly there is not. It is well known that all the writers on West India diseases during the last and present centuries admit this, but many of them-nay, the majority,―also admit, what is the fact, that the severe endemic of that climate is not this pestilence; that the former is liable to be mistaken for the latter; and that both are often confounded together, although they are as distinct, indeed more distinct from each other, than measles and small-pox. And in this Dr. Jackson errs with the minority, using at the same time terms which involve a theory, or mean nothing. Thus his concentrated endemic' must either mean the more malignant form of remittent, which I have described from frequent observation of it in warm climates, in the art. FEVER, by the name of malignant remittent, and which I know well is neither infectious, nor the pestilence now under consideration, the differences between which have been long since pointed out by many very intelligent and experienced observers." Vol. III., p. 164. Here Dr. C. makes the broad unqualified assertion that the Malignant Remittent (which, we have already seen, he admits not unfrequently assumes a continued type) does not exhibit infectious properties; and, in another passage a little further on, we find him laying hold of an extract from Dr. Jackson's writings, wherein allusion is made to the effects of crowding the sick together upon the diffusion and aggravation of the disease, to found a charge either of ignorance or of unfairness against this most esteemed physician. We leave the reader to judge for himself from its perusal : "The yellow fever," says Dr. Jackson, "during the reign of epidemic influence often strikes like a pestilence by the mere concourse of people in a close place; and if a mass of sick persons be collected into an hospital during the epidemic season, the common emanations from the sick bodies, whether saturated with contagious particles or not, often act offensively on those who enter the circle, and often appear to be the cause of the explosion of a disease which, without such accessory or changed condition of the medium in which men live, would have probably remained dormant for a time, and perhaps for ever. The instances of persons who have lived in apparent good health in simple epidemic atmospheres, and who have become sick soon after they entered into the circle of a crowded assembly, or the crowded wards of an hospital of sick, are numerous, and so well marked, that they stagger, on a superficial view, the opinion here contended for, of the non-contagious nature of the yellow fever.' To be sure they do, and being admitted by Dr. Jackson they become evidences of infection as strong as proofs from holy writ.'" P. 165. Indeed! Has not Dr. Copland himself told us that the Malignant Remittent may become infectious, "when a number of the sick are crowded together in badly-ventilated places, during warm and humid states of the air?" and has he not admitted the very same thing in respect of his "bilio-gastric fever," another denizen of those very regions where the yellow fever is most apt to be met with? We therefore see, from the data supplied by our author himself, that the character or attribute of infectiousness cannot be fairly set down as a diagnostic or discriminating feature of the genuine Pestilential fever; and thus the presumption that this attribute is not a uniform or necessary, but rather a contingent and occasional, property of the disease appears to be rendered more and more probable. We shall afterwards see how far this view is borne out by the history of the Eclair fever. Meanwhile, let us keep our minds as free as possible from all extreme and exclusive opinions, taking part neither with those who can see no cause save that of personal transmission in the work of morbific dissemination, nor yet with the ultraists on the opposite side, who have unguardedly asserted that Yellow fever is never propagated in this way. What has been said by an able writer in the Dictionnaire de Medecine et de Chirurgie, art. Contagion, of the labours of the late indefatigable M. Chervin in reference to one epidemic of the pestilence, may be applied with strict truth to almost every other one of which we have any published account: "Observe, in regard to this last subject, (viz. the error of attributing to infec tion what is often referrible to local causes), what occurred respecting the yellow fever epidemic of 1821 at Barcelona. Read the work of the French medical commission appointed to examine into that epidemic, and it will be impossible for you (admitting as true the statements therein contained), not to admit the existence of infection. But afterwards, when you have read the documents collected by Dr. Chervin with a degree of zeal and patience truly admirable, you will be convinced that the circumstances, which led you to be of the same opinion with the commissioners as to the reality of infection, are anything but conclusive." 18471 Is it truly Endemic anywhere? 207 So necessary is it to weigh and balance all things together, before we form our opinion. There is a subject, connected with the occasional outbreaks upon a large scale of the Yellow fever, that deserves much attention, but which, like every other point in the history of this perplexing disease, is surrounded with difficulties. Is it truly endemic, or does it occur only occasionally, in those countries where it usually appears? in other words, does it exist there in a partial or sporadic form in all years, just as the malignant Cholera does in the East Indies, or as the plague does in Egypt? or is it entirely extinct, save and except when it appears epidemically, as is usually the case with exanthematous fevers, viz. Small-pox, Measles or Scarlatina? Dr. Copland seems to adopt the latter opinion; for he says, when pointing out the diagnostic characters of the inter-tropical fevers that are so apt to be mistaken for each other, that "the remittent is endemic in warm climates, and in several temperate countries in warm seasons, especially those abounding with the sources of malaria: the ardent fever occurs only among persons who have recently arrived from cold or temperate climates into a very hot country; and true yellow fever appears only occasionally; and then the infection may either extend to a few only, the circumstances favouring its diffusion not existing, or to great numbers, the disease thereby becoming epidemic. Thus the first and second of these fevers are always occurring, especially the first; the third seldom, or after long intervals." Now here is a declaration in express contradiction of the opinion held by at least nineteen-twentieths of the medical men practising in the West Indies. That not a year passes over without a few sporadic cases, at least, of yellow fever occurring in those places that have usually been the scene of its epidemic visitations, is admitted by an overwhelming majority of those who have resided long in such districts. Indeed, we strongly suspect that Dr. Copland himself, notwithstanding the above quoted opinionwhich, we should mention, occurs in the 1st volume of his Dictionary, published 12 years ago-is now by no means satisfied of its correctness; for in the very last Part, when alluding to an outbreak of the disease at Port Royal Jamaica, we find him saying;—" it should be premised that the infection of this pestilence had lurked for several years, or even longer, in the most frequented sea-ports of the West Indies, as Port Royal, the Havannah, Vera Cruz, &c.' We may mention also that some of the most zealous infectionists, as well as others of the opposite party, have strenuously maintained that the disease is never entirely extinct in these and such-like places. The casual mention of this point naturally leads us on to the consideration of another, which has given rise to a vast deal of learned and elaborate discussion. The question to be determined is, whether the so-called genuine Yellow fever has been always an indigenous product of the West Indies, or whether it was conveyed thither, towards the close of the last century, from Bulam on the western coast of Africa; the malignant fevers that may have previously existed in the western hemisphere being, on this supposition, believed to have been only aggravated forms of the endemic remittent, but not belonging to the true specific pestilence which the appellation of the Bulam or black-vomit fever should, it is said, be employed to designate. Few indeed, in the present day, entertain the latter of these opinions; but, when it was first brought forward in 1794 by Dr. Chisholm, the confidence of his assertions, and the fortuitous outbreak of the pestilence in many of the West India islands after a lull of several years, had the effect of making a good many converts to his new and startling doctrine. Sir William Pym has always been one of its warmest espousers. We are glad, however, to find that Dr. Copland, albeit so energetic an advocate of the specific and essential difference between the genuine yellow fever and every form of endemic tropical fever, repeatedly and unequivocally acknowledges that the former had frequently broken out not only in the West Indies, but also in different parts of the United States, during the last, and even during the 17th, century; and, although he refers more than once to " the re-appearance (in 1793) of the malady in the West Indies after an immunity from it during many years," he judiciously avoids all allusion to the often-repeated assertion by certain ultraists that it was then imported for the first time from Bulam, on the African coast, by a vessel called the Hankey. As he therefore, with all his strong bias on the subject of importation, evidently considers the arguments of these gentlemen utterly unsatisfactory, by his not even so much as alluding to the name of this vessel, it may be very fairly presumed that the point in question is altogether untenable, and is not likely ever again to become a topic for much difference of opinion. That there was an outbreak of the disease, in an unusually severe form, in the West India islands in 1793, after many years of comparative immunity or rather mildness, cannot for a moment be doubted. The question of dispute is, whence did it come? Dr. Copland, as we have already stated, wisely avoids giving any definitive or peremptory reply. He merely says that it re-appeared. It broke out, at that time, first in Grenada; but not a word is said by him as to the producing, far less of any imported, cause of it in that island. He leaves indeed the impression on the reader's mind, although he does not make any positive assertion, that it spread thence by infection to the other islands of the West India Archipelago, and to different parts in the United States. Without canvassing this opinion at present, we shall merely remark that the course, which the disease seems to have pursued in its travels, appears to be anything but very consistentseeing that there was no restriction to free intercourse between the different islands-with the supposition that personal infection or direct transmission from one individual to another was the sole or principal agent in its dissemination. The pestilence broke out at Grenada in February, 1793. In July of the same year it made its appearance in Dominica, and in the very same month, at Philadelphia,* many hundred miles distant. Barbadoes remained unaffected until the beginning of 1794, and St. Domingo did not suffer until late in the course of that year; when it seems to have reached most of the West India islands. But it would be unprofitable to attempt to pursue the examination of a subject, on which such contradic * There seems to be no little difference of opinion as to when the disease made its appearance at New York, during this epidemic. Dr. Copland quotes the testimony of two gentlemen, Drs. Charlton and Bard. The former says that it appeared there in 1793, while the latter states he never saw a case of it until 1795. |