vice is adhered to, the Naval Practitioner may be assured that not only the chance of sickness will be greatly diminished in his own person, but that in a well regulated ship, aided by the earnest and judicions co-operation of the officers, the lives of the men under his charge may be preserved to an extent beyond his expectations, in ordinary seasons and circumstances.

During war, indeed, when the influx of unassimilated Constitutions is considerable, and especially after much exertion and active service, great sickness and mortality are, I fear, unavoidable; but, generally speaking, the result will depend upon the number of Europeans introduced, the time and situation chosen, and the exposure being limited at first, and gradually increased, or otherwise. It is, therefore, of the utmost consequence that bodies of men, whether soldiers or sailors, should arrive in that country at the coolest season of the year. (and if such can be selected as have previously served in a warm climate, they should invariably be preferred ;) that the former should be sent to the healthiest Islands, or positions at first; gradually exposed to duty under a vertical sun, and, instead of being quartered in the low, hot, alluvial ground, in the vicinity of the towns skirting the leeward bays, that their barracks should be built on hills of moderate elevation, sufficiently distant from marshy, damp ground, infested with insects, and from thickly wooded ravines, where the rank and luxuriant vegetation bespeaks the existence of exhalations unfriendly to health.

The importance of such selection was eminently exemplified by the saving of health and of life that accrued from the erection of new barracks for the troops, in a more interior and elevated situation, after the capture of Guadaloupe, in 1810, by Admiral the Hon. Sir Alexander Cochrane, then Governor of the Island. The humanity of this measure, and the judgment previously displayed by the Commander in Chief in the scite and construction of the Naval Hospital at Barbadoes, &c. have been warmly and deservedly eulogized by the most experienced men in both services; suffice it to mention the names of Drs. Jackson* and Mc. Arthur:-to me it may be permitted to pay a not less just and earnest tribute of respect to that unwearied benevolence which prompted his immediate attention to every proposal for the welfare of the seamen, and insured not only his concurrence, but active co-operation in whatever could add to their comfort in health, or alleviate their misery in sickness.

The healthiness of the ships stationed in the Caribbean Sea, will very much depend upon the state of discipline, and degree of attention paid to the crews It will be especially preserved by staying in harbour as little as possible; and by cruizing to the northward, or resorting to Halifax, or elsewhere, during the hurricane season, or when repairs which will require detention for any length of time in port are necessary. In fine, it will chiefly depend upon avoiding all undue exposure to the sun, rain, night air, fatigue, intemperance, and unwholesome shore duties; and upon attention to different regulations, and preventive measures, of which I have had ample oppor* Vide Jackson's Sketch of the History and Cure of Febrile Diseases, 1817pp. 386-and 392-3.

tunities of appreciating and stating the value, from the inspection, and the medical reports, of generally between sixty and seventy vessels of war.

Many of these being of a local and temporary nature, it would be needless to specify here; but I may shortly notice that the intermission of labour during the hottest hours of the day, working as much as possible under cover, giving a portion of cocoa before going to duty after sunrise, wearing flannel, injoining a soluble state of the bowels, serving spruce beer or sound wine instead of rum, and when this could not be done, issuing the latter of a certain age and quality, and finally, (for of the victualling, in the improved state of the navy, it is unnecessary to speak,) the adoption of every means to diminish the frequency of intoxication, were the chief of those measures from which the most beneficial effects were observed.

But of all occupations the most desirable to avoid is that of clearing a foul hold in the West Indies; and, therefore, whenever it is possible, ships requiring this to be done should be sent out of the country for not only is it highly dangerous in itself, on account of the noxious gasses disengaged, but because it is generally necessary to perform it in a secure, or land-locked, and consequently unhealthy harbour, such as that of Antigua.

Where the subject is of such importance, though at the risk of tautology, I request leave, in conclusion, to repeat, that the bad ef fects of staying in port too long at one time, and of harbour duties, particularly early in the morning and after the setting of the sun, as well as during his meridian power, cannot be too strongly adverted to; and, therefore, a measure of paramount importance is the employment of negroes, natives of the country, or at least of men accustomed to the torrid zone, in wooding, watering, transporting stores, rigging clearing, careening ships, &c. and in fine, in all such occupations as must subject men to excessive heat, or deleterious exhalations, which cannot fail of being highly dangerous to the health of the unassimilated European.

But the great object, I conceive, is to relieve the ships on that station, (the prospect of which, alone, has a wonderful effect on the health and spirits of the men,) so often that a foul state of the hold, and the necessity of cleaning it in that country, shall as seldom as possible arise. During the most active period of nearly eight years of the war, considerable sickness and mortality must necessarily have occurred; but in that time, I have likewise had the great satisfaction of witnessing, in various ships, and on various occasions, that a degree of health was maintained in that climate beyond my most sanguine expectations,—particularly latterly, when the season of active warfare being past, the necessity was precluded, and consequently the unwholesome duties of clearing the hold, heaving down, or undergoing lengthened repairs in the close barbours of the West Indies, were interdicted; and I am therefore led to conclude, that to avoid the stronger exciting causes of yellow fever, is, to a great extent, to escape the disease.

Observations on the locale of Yellow Fever, by Dr. FERGUSSON, F. R. S. Ed. Inspector of Military Hospitals.

Sec. IV. The principal West India towns and garrisons for the troops are situated on the leeward shores of the country, at the bottom of the deepest bays that can be found, as a protection to their trade against the winds from the sea. The soil must consequently be alluvial, and is often marshy. Nine-tenths of the towns are inclosed by high hills rising immediately behind them, which exclude the seabreeze that, in its natural course, ought to reach them from the windward side of the country. As their elevation is generally little above the level of the sea, we have abundant reason to conclude, that if the highest degrees of reflected tropical heat, defective perflation, and the miasmata that reside in marshy soils, or may be formed in the drier alluvial ones by heavy rains, can produce aggravated remittent fever, it must happen under such circumstances, especially where police and cleanliness are entirely disregarded.

The settlements of the planter, in like manner are formed, not on the elevated mountain ridge from which the periodical rains have washed away the soil, but in the alluvial ground beneath, where his labour can with more certainty be turned to profit. Nor is it to be wondered at, under such circumstances, that a body of raw troops or young civilians, come to settle in town or country, should be swept away by tropical fevers. The wonder is why it does not happen with more unerring certainty; for there are seasons, and even Courses of seasons under apparently similar circumstances of heat and moisture, when even the declared swamp is comparatively innoxious to the newly arrived Europe..n, and still more so to the seasoned inhabitant. This begets in the young adventurer or hardened votary of wealth, a fatal delusion of confidence which, though so often exposed by the melancholy recurrence of fatal fevers is never cured.

The pestiferous quality of miasmata does not appear to depend necessarily either upon aqueous or vegetable putrefaction, however frequently it may he found combined with both. Every one knows that the miasmata are not generated from the body of the lake or pool, but from its drying, or half-dried margins. The swamp is no more than this margin rolled up under another shape. Water, without being absorbed by the subjacent soil, gives out no febrific effluvia. One of the healthiest quarters in the West Indies, is that of the field officers on Berkshire hill, the bed-room of which is placed over a deep stone reservoir of water. But this said febrific miasma is very certainly generated from the paucity of water where it has previously abounded, provided that paucity be short of actual dryness. To the production of this a high atmospherical temperature is indispensable; and in proportion to the intensity of temperature is the intensity of power in the miasma produced, varying its effects on the human frame, from the ordinary ague of Europe, and the West India Mountain fever, to the highest degree of remittent, and yellow fever, which is never found remote from the level of the sea. It is comparatively innoxious to those who have had the good fortune to

become habituated to its influence; and attacks with singular peculiarity of selection the robust, the young, and the healthy, in their fi st approach to its abode. If these be granted, I think we may be able to explain from the various compositions of soil, its elevation, aspect, and texture, as affording capacity to retain moisture, why every dry one can be brought, during an uncommonly wet season, through the influence of tropical heat, into the state of a marsh that gives out noxious vapours; while a marshy one approaching to dryness through previous drought may be made perfectly healthy from the same abundant rains. Thus Barbadoes, which from its cleared calcareous soil, is far more salubrious, in general, than Trinidad, has been lately afflicted severely with the worst forms of yellow fever; while the latter island remained perfectly healthy. In both places it has rained abundantly-particularly in Trinidad, whose extensive marshes have been overflown; while the alluvial soil on the shelves of table-land at Barbadoes has been converted into a temporary swamp. So at St. Lucia, when the garrison on the lofty position of Morné Fortuné is healthy during the fine dry weather, the inhabitants of the town of Castrus, at the base of the same hill immediately below, and within half cannon shot, are visited by the worst fevers, and vice versa -The dry weather gives activity to the miasmata which the rains dilute, refresh, or condense, at the same time that they are forming pools, and temporary swamps on the shoulders of the hill, immediately beneath the barracks, on the summit of Morné Fortuné.

So a deep ravine, impervious to the rays of the sun, and free current of air, that has been a water course, may still, after its surface appears dried by the summer heat, retain sufficient underground moisture to give out the most dangerous miasmata-the more dangerous because the more concentrated for want of perflation;-and so, in fine, salubrious and insalubrious soils may, under such circumstances, change places, in regard to health; and localities in the neighbourhood of each, under the same modifications of climate, be very differently affected.*

It has been inferred that yellow fever belongs to a different family from that of intermittent, because it seldom occurs at the same time with, or breaks off, in convalescence, into ague. Ague indeed is not a common production in the hot low-land on or near the level of the sea-where alone the yellow fever is found. It is very rare, for instance, to hear of an ague originating in the leeward sea-port town of Basseterre, Guadaloupe, either amongst the troops or inhabitants; but in the barracks on the cool marshy hills above the town, at an elevation of less than a thousand feet, it is a very common disease, among officers and soldiers, while their comrades in the town are devoured by concentrated remittents. The same may be said of nearly the whole of the West India towns. They are all so marshy that,

*The reader is probably aware that some Authors, as Dr. Jackson and Mr. Doughty, consider an excess of the principle of Vegetation as the cause of Fever: "It would appear that the materials of vegetation abounding in excess, acted upon by a powerful cause, give out a principle, which not being expended in the growth and nourishment of Plants, is diffused to a certain extent in the atmosphere, occasioning a derangement of such bodies as come within the sphere of its action."-Jackson's Outline of the History and Cure of Fever.

in colder latitudes, they could not possibly escape agues, which however, very seldom originate, and are nearly unknown amongst them. The inhabitants of Barbadoes boast that they are exempt from agues, though the island has several marshes. Thus the reason is plain :There are very few ridges there of sufficient elevation to belong to the region of intermittents, even supposing their sides to be marshy, which they never are. The swamps are all in the lowest levels of the land; and when their morbific miasmata act upon the human body, they produce the greater or less concentrated forms of remittent fever, according as their powers are regulated by the temperature and climate of the season, or as the subject is presented under more or less favourable circumstances of seasoning, excitement, &c.

I am far from presuming to deny, says Dr. Fergusson, that there are fevers from pure excitement; "for soldiers and others have been attacked and died of yellow fever before they landed in the West Indies. or could be exposed to the influence of land miasmata in any shape." From this it would appear that a calenture, [the synocha of Cullen,] the pure offspring of heat, as pneumonia is of cold, runs a course similar to the yellow fever.

"To the argument that the highest degree of concentrated remittent or yellow fever, should neither remit uor break off into ague, "it seems sufficient to reply, that for any disease to observe regular "laws, it is necessary that the vital organs principally affected should "continue in a certain degree of integrity; that their functions "should only be disturbed and preverted to a given point; that they "should still be discernible as functions, and not be utterly over"whelmed and extinguished by the violent cerebral action and "speedy gangrene of the stomach that take place in aggravated yel"low fever. As the ulcer of a specific poison that would run a regu"lated course according to acknowledged laws, if it be driven to a "high inflammation or sphacelus, no longer belongs to the original "stock, and is emancipated from those laws; so the violent actions "of the above fever impair and destroy the animal functions by which "its crisis and remissions are regulated, or speedily engender a new "disease; as new as the conversion of an ordinary venereal chancre "into a phagedenic slough, through the application of a potential "cautery."

I may refer to the section on Bilious Fever, in the first edition of my work, for a similarity of doctrine.

By Malaria, Dr. F. means to express something that is more decidedly than miasmata the product of underground moisture, which can only be sublimated, so as to produce its specific effects, by long. continued solar heat-a more subtle miasm, in fact, of which the surface gives no warning, but of which the existence is proved from its effects on habitations that are placed in the draught of the dry ditches of forts, no matter how rocky or dry, if they are deep, and also of deep ravines. At Fort Matilda, in Basseterre, Guadaloupe, a wellraised artillery store-house and guard-room, placed in Bouchure, at the confluence of two of the ditches, was found to be utterly uninhabitable. The same malign influence affected the houses that were placed opposite the deep ravines of rivers, no matter how pure and