PRACTICAL RESEARCHES INTO THE DISEASES OF WARM CLIMATES. BOOK I. PRELIMINARY OBSERVATIONS. THE diseases most prevalent in warm climates have been treated of by authors whose opportunities of observation have been various, with regard to the particular sources of their experience, the circumstances peculiar to the patients who came before them, and the length of their practice. Of all these authors, there are few who have not contributed materially to our knowledge of the nature and treatment of these diseases. Some, however, have written more confidently than the nature of their experience warranted, conceiving that what had occurred to their observation ought to have been noticed by others, and that the results which they obtained should equally have been remarked by those who preceded, and be confirmed by such as may succeed them. But whilst some conceived they were instructing the rising profession from the purest sources of information, their inexperienced readers seldom stopped to inquire into the extent of that information, or the peculiar circumstances under which it was obtained; they seldom considered, that although disease has certain characters to-day, it may have very different ones at another time, according as the nature of its causes may vary, and as the circumstances more immediately related to the patient may change. Practitioners whose experience of the diseases of warm climates has been limited to those who have recently arrived from a cold country, possessed of a phlogistic diathesis and plethoric habit of B body, heightened by living on salted animal food and a liberal use of spirits, perceiving vascular action increased, and even tumultuous, most properly deplete their patients, and find their practice successful. Elated with success, and without considering that the character of the disease and the issue of the practice are the result of the particular circumstances of the patients, they become prone to contend that the fevers and diseases of the country are of the same nature with those which they have observed in the narrow sphere of their experience, and are to be cured by the same means which they have practised. Other practitioners have observed the diseases of intertropical countries under other or almost opposite circumstances, and owing to those circumstances, in connexion with an essential difference in the nature of the causes productive of these diseases, have been led to employ a method of cure very different from that now alluded to. They write on the diseases of warm climates, and, as they conceive, from experience. As an account merely of what they had themselves seen in the particular field in which they were labourers, their observations would have been valuable; but when they generalise from the very limited data they have obtained, and assert that what was true as respects that which came before themselves, under particular influences and circumstances, must be true also of all that has been observed, or will be observed in future,-they may influence the inexperienced, but they will never command the assent of the practitioner, who, taking nature as his guide, follows the dictates of his own judgment, and endeavours to found his views of diseased actions, whether observed between the tropics or in the temperate zones, upon the nature of the causes, the vicissitudes of season, climate, endemic and epidemic influenees, and still more particularly upon the circumstances which are proper to the individual. Amongst the various works which have already appeared, there are very few which have proceeded from authors whose experience in warm climates has been diversified to that extent which could have been desired. They who have seen the diseases of those climates, only as they appear in ships of war or merchant ships, either at Diamond Harbour, or Batavia, or Vera Cruz, or Kingston, during a few weeks' or months' stay at these ports, may be very able and safe guides as respects the diseases which occur in ships recently arrived or stationed at these places, at particular seasons of the year; but they can never be considered authorities as to the nature and treatment of the diseases of the country, as they occur under every variety of cause, influence, and circumstance by which they are modified. Nor can they be always implicitly trusted as regards the maladies of the class of individuals to which their practice has been limited; for much will depend, as to both the nature and treatment of the diseases, upon the length of time ships have been navigating within the tropics, the country from which the crew has been obtained, the time which has elapsed since they left a cold country, the manner in which they have been fed, the quantity of spirits they have been allowed, whether they have been before in a warm climate, whether their stay in it was long or short, or at a remote or recent period, and whether the susceptibility of their frames and the rigidity of their fibres have been subdued by previous attacks of what is usually called seasoning fevers. Nor can, on the other hand, army physicians or surgeons, whose observations have been limited to a particular country, district, or situation, and to a class of men very distinct in their habits and occupations from the community generally, be received as competent authorities upon a subject which has reference to all classes of men, to natives as well as Europeans,-and to those amongst the latter who have passed the greater part of their lives in a warm country, equally with those who have recently arrived in it. When, however, their opportunities are extensive and diversified, there is no class of practitioners who have more ample means of advancing our knowledge of diseases: they have complete control over their patients; and new remedies and improved modes of treatment may be employed, and post mortem examinations may always be made by them without restriction. Unfortunately for the state of medical science, as regards intertropical diseases, written opinions respecting them have been too often furnished by those to whom many of the above observations very closely apply. And still more unfortunately for the young practitioner, upon his arrival in warm climates, instead of endeavouring closely to analyse the symptoms of the disorders which come before him, and to judge impartially respecting them, assisted by the lights which science has afforded him, his mind is biassed by the opinions promulgated by those whose sources of experience are of the description already noticed, and he surrenders his judg ment to their direction. The unreservedness with which their pathological descriptions and curative precepts are delivered, inspire him with confidence as to the universality of their application, and he adopts the treatment inculcated, until the results open his eyes, and he at last perceives that numerous circumstances modify the character of intertropical diseases, as well as those of temperate climes; and that the treatment, in order to become eminently successful, must be always suited to the exact aspect which these diseases assume, as far as that can be determined, aided by enlightened views of the operations and laws of the animal economy in health and in disease. There have appeared, however, some authors on intertropical diseases, to whom the foregoing remarks are not intended to apply, whose experience has been sufficiently extensive to convince them of the difficulty of the subjects on which they have endeavoured to instruct the profession, and at the same time to render them less confident as to matters, the relations of which have not been before them in that full and satisfactory manner which is requisite to the formation of sound opinions respecting them. Such writers are the landmarks of our profession, forming the best guides by which the inexperienced navigator through the dangerous channels of our science, can secure the safety of those committed to his care, and promote his own reputation. It would have been desirable that, in the place of the numerous and contradictory opinions upon intertropical diseases which have issued from the press during the last half century, and bewildered the inexperienced reader, aud which have been advanced chiefly by those whose field of observation and length of practice have been extremely limited,—the results of extensive and diversified experience of disease, amongst long residenters as well as recent comers into warm climates, had been furnished the profession; that the disorders appearing amongst Europeans, under every variety of circumstance and exposure in which they have been placed, had been faithfully reviewed, and considered in relation to the nature of the causes and the condition of the individuals on which these causes operated; and that the disorders occurring under similar circumstances, and from the influence of the same kind of causes, amongst the native inhabitants, had also received that degree of attention which the subject, as to both its inherent importance and the interest it is calculated to afford, when compared with that of European sickness, so unquestionably deserves. It is, however, to be much regretted, that those who have enjoyed extensive opportunities of observing the diseases most prevalent in warm climates, as regards both the length of their experience and its diversity among all classes of Europeans, civil, military, and naval, as well as among the native inhabitants,—who have seen those diseases under every vicissitude of season, and of public and civil service, in a great variety of countries and circumstances,― have, nevertheless, either allowed the results of their experience to perish with themselves, or continued to withhold information which could not fail of proving serviceable to their inexperienced brethren. It is chiefly with a desire of setting an example to those who have enjoyed such opportunities, to break the silence which they have so long kept, and to endeavour to form a part of what they have themselves acquired to those who may in any way stand in need of it, that I appear before the public. I shall obtain my object, if I find the attempt which I have imperfectly made be followed more successfully by others, abler than myself, to do the subject its deserved justice,—if others, who have seen and observed for a long series of years, the derangements produced upon the human constitution, of Europeans particularly, in warm climates, shall hereafter furnish to their inexperienced successors in the same field of exertion, the fruits of their matured judgment and observation, and thus fill up the sketch which I have imperfectly attempted to draw. And, above all, I shall be gratified, if what I am about to communicate shall lead the well-educated medical practitioner, proceeding to intertropical regions, to observe and to think; and to act rather from the rational deductions which he may form from a careful and comprehensive view of the circumstances producing and influencing the career of disease, than be guided by the confident and unreserved dicta of the imperfectly informed writer, whose advices are suitable only to particular circumstances, which circumstances may turn up but occasionally, or even rarely, in the general revolution of human events. The practitioner who shall thus endeavour, upon his arrival in a warm climate, to observe and to reason upon the derangements taking place in the human frame, will soon become the most decided and the most successful controller of their course, will know when and how he should attempt to arrest them; and, when this idea cannot be entertained, will conduct them with the greatest safety to a successful issue, when it is in the power of art to accomplish this desired object. He will, moreover, observe that the diseases which have been described and held up to him, with regard both to their nature and treatment, as forming of themselves a distinct class, proper to intertropical climates, frequently occur in other countries; and, like other disorders, are merely functional at their commencement, but quickly running their course, and generally assuming a more acute aspect, owing to the concentrated nature of their causes, the |