have not seen them in the same or even similar light with Sir Gilbert Blane; for I believe, that, since the time of Dr. Chisholm, no respectable practitioner in the West Indies, who has seen much of the disease, has believed it to be inherently and essentially contagious. And it is passing strange, that Sir Gilbert Blane, who has taken so much pains to teach us the right mode of reasoning on medical matters, should here turn round, and tell us, that all reasoning in such cases, is not only idle but pernicious! I desire to treat Sir Gilbert Blane with respect, and for his character generally, I do feel respect; but such feelings cannot be forced; and I cannot respect dictatorial intolerance in any man, or any place, more particularly in the exercise of a liberal, but not exact, art; and I cannot admire the temper, which would lead a man, in possession of executive power, to dismiss from the service of their country such men as could not in conscience subscribe to his articles of professional faith." 82.

Dr. Wilson, in this memoir, takes an extensive range over, not only various countries between the tropics, but various localities in the same countries. This memoir is exceedingly creditable to our author's researches, inquiries, and judgment. Dr. W. dwells a long time on the subject of marsh miasmata, and has unnecessarily accumulated proofs that we cannot clearly trace the cause of the yellow fever of the West Indies to mere exhalations from soils of a marshy character. This has long been given up; and the more general opinion is, that the cause of fever is an emanation from the soil, whether marshy or not, which gives rise to fevers varying according to the nature of that invisible, and hitherto unascertained agent, or the soil which produces it. Our readers are aware that this is the doctrine which we have uniformly maintained in this Journal, from its commencement. We have often employed the term "febrific miasm," as much freer from objection than marsh effluvium, or vegeto-animal miasma. The term malaria is, we think, somewhat objectionable, since it conveys the idea of the cause being essentially connected with the air, though reason and observation tell us that the cause springs from the earth, and is only suspended in, or wafted about by the air. But it is now time to proceed to the author's "new opinions," regarding the cause of yellow fever.

THIRD MEMOIR.

Dr. W. observes, that the West India islands, and parts of the adjacent coasts of South and North America, constitute the proper soil, and are the perpetual sources, of West Indian fever. From the mouth of the Amazon to Charleston in one VOL. VIII. No. 15.

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direction and from Barbadoes to Tampico in another, the causes of this disease are in constant, though unequal force It sometimes, as is supposed, extends to New York, and even to the southern parts of Europe. At all events, it reaches from the Equator to the 32d degree of North latitude-and from the 60th to the 98th degree of West longitude. Now, the space included in this vast range exhibits a great variety of aspect, soil, and atmospheric temperature; and, on comparing these with other parts of the world, we can perceive nothing to account for this uniform fertility in the production of a febrific miasm causing yellow fever:--nothing in the heat of the air, the quality of the soil, or the condition of the subject. We must, therefore, after all, take for granted that there is a something generated in the earth, and diffused in the air, to account for this wide spread of fever. Dr. W. comes to the point which we have so long insisted on. This atmospheric influence, it is reasonable to suppose, is derived from the earth's surface; for we have no notion-can have no notion, of any thing contaminating the air, excepting the earth or its productions.'

Dr. W. thinks that this cause, if ever to be discovered at all, will be found by a careful and scientific survey of the more superficial parts of the crust of the globe. We much doubt whether the labours of the geologist and chemist will ever be able to detect the febrific miasm. But, by this, we do not wish to discourage their inquiries. Like the search for hidden treasures, the harvest will reward the toil. This task our author assigns to the medical officers of the army, scattered, as they are, in various parts of the world, and qualified as they are to undertake the investigation. In the mean time, Dr. Wilson himself throws out some hints which he hopes may prove serviceable to those who have better opportunities for prosecuting the inquiry.

He remarks that lime, of secondary formation, is a predominating ingredient in the surface of the West Indies; while, in many places, there is much recent volcanic matter. Where such kind of surface is most conspicuous, from being scantily covered with earth or herbage, there the West India fever is peculiarly frequent and severe-"if the more palpable cause of the disease exist in the vicinity." The foregoing position is exemplified by the following curious topographical fact.

"Rock Fort is placed three miles east of Kingston, at the eastern extremity of the plain of Liguanea, where it is narrowed to the breadth of a few yards, being bounded southward by the sea, and northward by a precipitous mountain. The contracted and scanty soil, east and west, is alluvial, but dry, with the exception of a small spot to leeward; and the appearance of the vole would not

give an impression of insalubrity, the sea washing one side, the structure beneath being coral, and the mountain, which rises behind a naked calcareous mass, destitute of soil and vegetation. Yet this has been one of the most fatal spots to our troops of any in the West Indies, the detachments employed in its garrison having been swept off in rapid succession by West Indian fever. The officers' quarters stood at a short distance from the general barracks, on a dry indurated foundation, close to the mountain, and occupied presumptively a more healthy site than even the general building. But experience has shown that it was more unhealthy. So unhealthy was it, and so concentrated is the cause of fever upon it, that scarcely an individual quartered there, if lately from Europe, escaped with life. It is for the present abandoned." 128.

Even the naval force suffered severely on this station. A well of excellent water springs on this spot, and there the boats' crews were employed in watering the ships. Entire crews were swept off by the fever, and scarcely any escaped who visited that fatal spot.

Stoney Hill is next adduced. The barracks there stand 1300 feet above the level of the sea, and the air is comparatively cool; there is nothing like a marsh in the vicinity: yet it is extremely unhealthy. Dr. W. informs us, however, that this hill, from its base to its summit, is one great mass of calcareous rock, intersected by deep fissures, and split, in many places, into large fragments, heaped on each other, and crumbling into powder. Over its whole surface, there is scarcely any soil, and little grass, weed, or herbage of any kind. "But it has been, and is still, generally covered with forest trees, the roots of which are seen expanded over, and clinging to, the naked rocks, the extreme fibres dipping into the crevices, and hiding themselves amid the detritus of the rock, decaying leaves, and other ligneous matters which are lodged there." We apprehend that Dr. Macculloch, and others of that school, would be at no loss to find a source of malaria even on the declivities of Stoney Hill.

"Fort Haldane, at Port Maria, occupies the extreme point of a promontory which projects considerably from the main land, and divides the bay into two basin-like recesses. The promontory, which is 158 feet above the sea, is about 200 feet across, is so nearly perpendicular, and so much alike in its faces, that it has the appearance of an artificial structure reared for the defence of the harbour. It is formed of a pure carbonate of lime, so white and regular as to look like a white-washed wall; it is level, smooth, and dry on the surface; and when it was chosen as a point of defence for the construction of a fort and barracks, it was probably thought to be one of the most healthy situations in the West Indies. Merely looking at it as an elevated, regular, dry mass of limestone, washed

on three sides by the sea, we should think so still; but the experience of the troops, and the sick returns, prove it to be, in every way, the reverse. So productive of fever and so deadly has it proved, that for some years past it has not been garrisoned. In November, 1824, on urgent representations by the local authorities, that troops were necessary, from apprehended insurrection of the slaves, a detachment of the 50th regiment was sent to occupy the barracks. Fever appeared among them so early, and was so destructive, that, at the expiration of six weeks, the detachment was removed, having lost, I believe, one-third of its number from fever, and the remainder mostly suffering from its effects; and this happened at a season generally healthy, to troops who had been some years in Jamaica, and who were landed in health. Two streams fall

into the bay, one on each side of the headland, at about a quarter of a mile distance. They move slowly, and their banks are covered with mangroves, which, it is to be presumed, furnish the more palpable cause of the fever; but it is remarkable that the inhabitants of the village of Port Maria, which is situated on both sides of one of the streams, do not appear to suffer from their situation." 130.

There are many examples on record similar to the above. It is by no means impossible, that those who live in the very vicinity of a source of malaria may escape, while those who are elevated above this source, and at some distance, may sustain its most deleterious influence. The current of the prevailing winds, and other circumstances should here be carefully investigated, as miasmata may be carried towards, or descend, and become accumulated on, a lofty eminence, in the neigh. bourhood of a malarious source, while the same miasmata may never acquire a sufficient concentration in the spots which gave them birth. We believe that this explanation will apply to many unhealthy localities.

Dr. Wilson goes on to give us very interesting sketches of the medical topography of Port Royal-Port of Spain-Fort Louis in the Island of Martinique--Guadaloupe-St. Domingo --Barbadoes, and many other places, showing how very generally it happens, that high and rocky elevations in the vicinity of mangrove swamps or morasses, are ten times more destructive to life, as the hot-beds of yellow fever, than the valleys or swamps themselves.

The author has been particularly struck with the prevalence of lime in all those situations, in the West Indies, which are remarkable for insalubrity, but modestly declines drawing any general conclusion as to the connection of the one with the other. He therefore, proceeds to what he calls the more palpable cause of yellow fever.

"This, I believe, is furnished by wo ing a gaseous product of

trees and shrubs, in a state of decomposition; generally given out by them in a cut or dried state, but which may arise from a living forest, trees being capable, in different parts of their frame, of simultaneous growth and decay; and further, that wood, after it has passed from the green to the dry state, is still capable of generating the cause, certain degrees of heat and a certain quantity of moistture being supplied. I therefore believe, that decomposing vegetable matter, in a certain sense, but not in the sense generally received, furnishes the cause of West Indian fever; as it is not to herbaceous but ligneous matter that I trace it, and on which I shall endeavour to show its dependence." 139.

This, we conceive, is a nice distinction, and, considering that hill-fevers, wood-fevers, jungle-fevers, have been described for 20 or 30 years past, we see no great" novelty" in the opinions here emitted. Dr. Wilson goes on to prove his ligneous origin of yellow fever, by showing that it occurs in ships, where "marsh miasmata are not necessary to its production." Our author does not attempt to explain "what the manner of that process is, and what is the nature of its products;" but only pledges himself to prove that such febrific process does occasionally exist in ships. He objects to the supposition, that a foul hold can be the cause of the sickness--principally it would. appear, from what occurred in the Iphigenia and Rattlesnake, where the yellow fever prevailed extensively, although no foulness could be detected in their holds, and circumstances rendered it highly improbable that the disease could have arisen from terrestrial exhalations. One of the medical gentlemen appointed to examine the above-mentioned ships, and report on the cause of the sickness, was Dr. Bancroft; and it appears that the fever in question completely upset all his former writings, as to the origin of the disease!

"But Dr. Bancroft, whose labours in this field are so well known and so highly appreciated, who has collected so much information and exerted so much talent to prove, that this disease depends on earthy exhalations for its cause, as certainly as does intermittent fever, finds the whole of his elaborate and highly-finished structure sapped by the fever in the Iphigenia. He finds there a stumblingblock, which he had not expected and cannot remove, and he fairly confesses the insuperable nature of the difficulty." 151.

All the usual sources of the febrific miasm having been disproved, Dr. Wilson comes to the conclusion, "that it arises from the decomposition of the wooden materials of the ships themselves, and from such loose timber as they may contain.' Dr. Wilson's arguments do not carry conviction to our minds; for we cannot imagine why the same decomposition should not go on in all climates of as high a temperature as the West In