timonial powder was afterwards made. When debility only remained, decoction of bark with nitrous acid, was found useful. In some cases, attended with great febrile stricture on the skin, the cold ablutions were used with success. In the Leopard some mortality prevailed.

This view of the subject leads to a practical inference of considerable utility, viz. that when necessity compels us to penetrate through those insalubrious woods, jungles, or marshes, we should seTect that point of time at which we are least likely to meet those miasms, whether in their ascending or descending state. seems to extend from three to six o'clock in the afternoon; that is, afThis period ter the greatest heat of the earth and air, and, consequently, the greatest evaporation; and before the condensation and return of such exhalations as rose during the day, and which combine with those still issuing from the heated soil, for some time after sunset. It is but too well known, that the cool of the morning, of the evening, nay, in many instances, of the night, is generally pitched upon for wooding, watering, and other duties on shore, to the great risk of those concerned in such dangerous occupations.

An attention to the above rule, [founded on facts as well as reasoning, would certainly be productive of much good; particularly when it is considered, that the human frame during the portion of time above alluded to, is, perphaps, better fortified against the impression of marsh effluvium, or other debilitating causes, than at any previous or subsequent period in the twenty-four hours. The seaman makes his principal meal at mid-day; he is then served his allowance of wine or spirits, and if a couple of hours rest is allowed at dinner, his energy and strength are much greater at three o'clock, than early in the morning or late at night. The European may object to this, by observing that the body and mind, recruited by sleep, are most vigorous in the morning. But I well know, from personal experience, that in tropical climates, and particularly during the rainy season, which compels all classes to pass the night between decks, the rest obtained from interrupted, I might say, stifled sleep, is very trifling. Indeed, a general languor, lassitude, and want of appetite prevail till towards noon, when dinner, wine, and an hour or two of repose, give a tone and activity to the system, which continue till the evening. This is the time, therefore, when we can resist the agency of marsh effluvium better than at any other, and of course should be selected, especially since it is at this period that the miasmata are most diffused through the higher regions of the atmosphere, and consequently less potent in themselves. The next three or four hours, viz. from six till nine or ten o'clock, appear to be pregnant with danger to those on shore. Within the tropics there is little or no twilight; immediately the sun withdraw, his beams, [six o'clock.] every thing is involved in darkness; dews and vapours fall from the upper regions of The air, and exhalations still continue to spring from the tepid marshes to meet them. At this juncture, therefore, in the places and seasons alluded to, the stratum of atmosphere in immediate contact with the surface of the earth, must be highly saturated with a principle but

too destructive to human health and life; and the system is then, too disposed to its reception, in consequence of the exhaustion produced by the heat and labours of the day, and the torpor induced by the coldness of the evenings.

This reasoning will be illustrated and confirmed by the following authentic particulars. In the month of November, 1804, two parties of men, belonging to his Majesty's ship Tremendous, were employed on shore, at the Island of Madagascar; one party, during the night, filling water, the other cutting wood during the day. Four of the night party were attacked with the endemic fever of the country,— and three of them died. The whole of the day party escaped the fever, though exposed to an intense sun, in the laborious occupationof wood-cutting.

About two years after this, his Majesty's ship Sceptre in the same place, and upon a similar occasion, experienced a still greater disaster among her watering or night party, to whom the mortality was confined. Some interesting particulars respecting this fatal occurrence, I shall give in the words of the surgeon, Mr. Neill.

"The fever which attacked our watering parties at the Island of MaJagascar, bears a striking resemblance to the endemic fever of the west;-like that too, it was not a contagious disease, of which we had the most cogent proofs, and corroborated what we witnessed at a former period. I believe that the exciting cause of this disease was confined to the site of the watering place, as no person was affected upon the wooding party, though constantly exposed through the day. The deleterious effects of nocturnal exposure were particularly exemplified here, by the disease raging most violently among the marines, who were on shore at night for the protection of the casks, and to whom the mortality was confined. The fever made its appearance among some of the same party who did not pass the night on shore, but in them it was infinitely milder, though similar in type and general symptoms. The watering place was encompassed from the sea by an amphitheatre of hills; and in nearly the centre of this ran the rivulet from which we filled, situated in a marshy plain, surrounded with some trees of the palm kind, and a thicket of jungle. The wooding place, on the other hand, was a dry sandy soil, though standing equally low, and covered with brush-wood, jungle, &c. in the same manner as the other. As the more minute features of the disease are described in the journal, I shall only remark, that it exhibited something of the remittent type, inasmuch as the paroxysms were more conspicuous and violent on alternate days; and on the intermediate, the system seemed less oppressed and more tranquil, with a different cast of features in the countenance; but there never was any thing like an apyrexia. The general treatment adopted in these cases, and which the journey developes, consisted in blood-letting, purging, and exciting ptyalism; the pre-eminence of which practice, several years experience in this country has amply confirmed. My sentiments have been so often expressed on venesection, that I need not repeat them. With respect to purgatives, I have always observgreatest relief to follow, when they took full effest That

they are beneficial in every stage of the disease, I infer from this ;that the pulse, from being depressed, weak, and void of energy, becomes open, energetic, and bounding to the surface with a corresponding animation in the countenance, after copious catharsis, even in the last stage of debility.

The next and only remedy, where blood-letting and purging do not check the disease at once, in its infancy, is mercury to excite ptyalism. I say ptyalism, for soreness of the mouth will not secure the patient in this endemic. In many of the fatal terminations, the mouth was slightly affected; but we never were able to excite ptyalism. Wherever this last could be induced, a revolution, as it were, in the whole train of morbid symptoms instantly succeeded, and a healthy train supplied their place! This revolution was most strikingly evinced in the functions of the bowels, by the evacuations becoming, all at once, copious and feculent: a circumstance, which previous to ptyalism, no purgative, even of the most drastic nature, could effect."

Although the latter part of this document is foreign to the subject for which it was introduced, yet I trust it will be considered interesting. It is satisfactory to me, since it strongly corroborates what I have advanced lately on the treatment of the Bengal endemic, both in respect to bleeding and ptyalism; the former being rather heterodox in India. I have only to remark, in reference to the striking coincidence of our practical views, that the above document was never penned for my inspection, nor that of the public. The sensible and well informed author of it, (Mr. Neill.) is alive, and can contradict any misrepresentation of his sentiments.

I shall here observe, once for all, that the foregoing remarks will equally apply to all other documents and narratives introduced into this essay, in addition to my own personal observations. They are strictly authentic; being the spontaneous records of facts, commemorated without preconceived theory or preconcerted design. I need not say how much their value is enhanced by this consideration.

In the account of the Batavian endemic, some other striking instances, corroborative of the opinions here advanced, will be related. In the mean time, the above examples will be sufficient to justify the rules I have laid down, aud put future navigators on their guard, where disease and danger lurk in concealment.

And here I cannot help noticing the apathy or impolicy, which still allows Diamond Harbour, the principal anchorage of our Indiamen, to continue backed and flanked by woods, jungles, and marshes, to the annual destruction of one-fourth of the crews of such ships as load and unload at this place! The objection to clearing the Sunderbunds, has been founded on the idea of their presenting an impenetrable barrier to the incursions of an enemy from that quarter; but the government does not seem to be aware, that to secure us from a domestic foe, it is by no means necessary, in this instance, to throw open the way to a foreign. A semicircle of cleared and drained ground, even of six miles in radius, [not a thirtieth part of the Sunderbunds, and scooped as it were, out of their centre,] would sufficiently protect the anchorage and warehouses of Diamond Harbour,

from the baleful influence of those exhalations we have been des→ cribing.

That the woods and jungles might be cleared, admits of no doubt; and that the country round Diamond Point might either be drained, overflowed, or submitted to the flux and reflux of the tides, any one of which measures would afford comparative security, can hardly be denied. To add to this security, one or two narrow semicircular belts of wood might be interposed between Diamond Harbour and the confines of the cleared space, to arrest any effluvium disengaged from the surrounding wilds or marshes, and conveyed by the breezes towards the aforesaid anchorage. All writers agree, that marsh miasmata, although much less limited in their rage than the matter of contagion, would be perfectly harmless after traversing a much shorter route than that proposed; but where native labour can be so easily procured; indeed, where the convicts alone would be equal to the undertaking in a very few years; and finally, when it is considered, that this salutary step opens not any facility to the irruption of an enemy on the southern frontier of Bengal, we can hardly doubt that the attention of the company will, ere long, be directed to so important a measure. Till then we can only remark, that the further from shore, and the lower down the river ships lie, so much more healthy will be the crews. On this account Saugur Road is more eligible, in regard to salubrity, than Kedgeree; and the latter much. less dangerous than Culpee or Diamnod Harbour. This was amply proved by the comparative mortality in the Caroline, Howe, and Medusa frigates. The two latter, by anchoring higher up than the former, lost at least six times as many men, from fevers and fluxes. Indeed, one was obliged to take a cruise to sea, and the other to retreat back to Saugur Roads, to avoid depopulation! Some suggestions will be given hereafter in regard to the means of obviating the effects of marsh effluvium, even at Diamond Harbour, the focus of this destructive principle.

In what manner, or through what channel it is conveyed to the sensorium, so as to produce its effects on the constitution, we are nearly ignorant. A general idea prevails, that the stomach is the medium through which the matter of contagion acts; and, by analogy, that marsh miasmata take the same course. But when we consider, that at each inspiration, the atmosphere impregnated with this principle is largely applied to the delicate texture of the lungs, it is not difficult to conceive, that it may pass into the blood, [if it is in any case absorbed,] as readily as oxygen. There are, besides, the schneiderian, and other membranes of the nares and fauces, to which it must have constant access, while there is but one way for it to pass into the stomach, viz. along with the saliva or food. Further, when we see this principle, in a concentrated state, produce fever in a very few hours, with high delirium, can we suppose that it enters the system by the circuitous route of the alimentary canal and lacteals? If it be said that it acts through the medium of the nerves of the stomach, why not through that of the olfactory, which is a shorter road? Indeed, from a near view of its effects, there is every reason

to suppose that the brain and nervous system suffer the first impression and shock. To those effects, then, we are to direct our atten. tion.

I believe it is nearly an unanimous opinion, at present, that both marsh and human effluvia are directly sedative or debilitating in their nature. Dr. Rush, indeed, uses the term, "stimulus of contagion," in almost every page of his work on Yellow Fever; but like the more celebrated "stimulus of necessity," it may be quietly laid in the "tomb of all the Capulets." By Dr. Jackson, the cause of fever is compared to electricity. "It seems to accumulate in the system by a regular but unknown process: in a certain state of accumulation, it seems to explode in a manner similar to the explosions of electricity." The delirium and violent action early apparent in the jungle fever, might countenance the idea of a stimulus, and that the subsequent debility was of the indirect kind. I have heard this opinion maintained on the spot, by medical gentlemen; but if we narrowly inspect the train of morbid symptoms, we find more of irregular than increased action; more of apparent than real strength. If we carefully observe the delirious patient writhing and struggling under the first impression of this cause, we find the efforts not only momentary and less effective than healthy exertions, but accompanied even at the instant, and immediately succeeded by tremor and other marks of debility. The premonitory symptoms too, are all indicative of decreased sensorial energy. The mind is wavering and unsteady; the appetite languid; the secretions, particularly the biliary, diminished; and the bowels torpid. Notwithstanding the determined phraseology of Dr. Rush, therefore, we may still adhere to the opinion of the venerable Cullen, that marsh, as well as human effluvium, is sedative. Dr. Jackson, indeed, will not allow it to be either stimulant or sedative, but a kind of irritant; yet he gradually slides into the admission of its sedative nature: "It however appears, from the most general view of things, that the febrile cause is a cause of irritation, disturbing, but not increasing in a natural manner, the action of the moving fibre. On the contrary, interrupting, impeding, and as it were, suspending the operations essential to health and life; by which means the expression of its effects principally consists in debility and impaired energy."t

The space of time which intervenes between the application of this poison to the system and its ostensible operation in the form of fever, depends on the degree of its concentration, and the predisposition of the patient. It will, for instance, be found in some places so powerful, that a man in perfect health, by remaining on shore during the night, in marshy situations, and wet or autumnal seasons, shall have the fever violently the next day, and die on the third or fourth. On the other hand, it may be applied in so dilute a state, as to require eighteen, twenty, or even thirty days, to bring on fever; and even then, perhaps, only in consequence of some of the nume

* Outlines of Fever, p. 247.

+ Outlines of Fever, p. 253.

Dr. Jackson says two months, and Dr. Bancroft nine or ten