!:!£>!:! i «9J £# '#ff!i UNITED STATES OF AMERICA FOUNDED 1836 WASHINGTON, D.C. OPO 16—67244-1 PHYSICAL AND TOPOGRAPHICAL SKETCH MISSISSIPPI TERRITORY, LOWER LOUISIANA, A PART OF WEST FLORIDA BY GARRETT ELLIOTT PEJVDERGRAST, OFNATCHES' MEMBER OF THE p"KI; , \A ' MEDIcT/Pt'" AND CHYMICAL SOCIETIES, AND OF THE AMERICAN LINNEAN SOCIETY. " For man loves knowledge, and the beams of trutli More welcome touch his underftanding's eye, Than all the blandifhments of found his ear, Than all of tafte his tongue." AtCENSIDL f '*^M?ty tk & PHILADELPHIA. PRINTED AT THE OFFICE OF THE GAZETTE OF TtCEr——"* UNITED STATES. 1803. AN INAUGURAL DISSERTATION, FOR THE DEGREE OF DOCTOR OF MEDICINE, SUBMITTED TO THE EXAMINATION OF THE REV. JOHN ANDREWS, D. D. PROVOST, PRO TEMPORE, THE TRUSTEES, AND MEDICAL PROFESSORS OF THE UNIV SITY OF PENNSYLVANIA, ON THE EIGHTH DAY OF JCNE, 1803. O /".(T J/? **» ) TO CASPAR WISTAR, M. D. PROFESSOR OF ANATOMY, SURGERY, AND MIDWIFERY, IN THE UNIVERSITY OF PENNSYLVANIA, ONE OF THE VICE PRESIDENTS OF THE AMERICAN PHILOSOPHICAL SOCIETY, &c. &c. THE FOLLOWING PAGES ARE INSCRIBED, AS A MARK OF ESTEEM, FOR HIS INGENUOUS FRIENDSHIP, AS A MAN, AND HIS UNREMITTED EXERTIONS IN THE CAPACIOUS FIELD OF GENERAL SCIENCE, AS A PHILOSOPHER ; BY HIS FRIEND, THE AUTHOR. TO BENJAMIN S. BARTON, M. D. PROFESSOR OF BOTANY, NATURAL HISTORY, AND MATERIA MEDICA, IN THE UNIVERSITY OF PENNSYLVANIA, ONE OF THE VICE PRESIDENTS OF THE AMERICAN .PHILOSOPHI- CAL SOCIETY, &CC. &C. SIR, That your difpofition to diffufe Natural Knowledge, in your intercourfe with your fellow men, may ever fecure you the fame which you now enjoy, and which is the natural inheritance of fuch talents as you poffefs, is the cordial wifh of Your friend, G. E. PENDERGRAST. TO JAMES WOODHOUSE, M. D. PROFESSOR OF CHYMISTRY, IN THE UNIVERSITY OF PENNSYLVANIA, &C. &C. SIR, It affords me great pleafure, that I have it in my power thus publickly to tender you my refpe&s, as well as to acknowledge my obligations for the much ufeful information derived from your publick as well as private inflru&ion, and for the polite perfonal attention with which you have been pleafed to honour me, while attending the Univerfity of this place. G. E. PENDERGR AST- i t, A TOPOGRAPHICAL SKETCH. X. HE tra£t of country to which my obfervations are more particularly confined, and Medical Topogra- phy of which it is the obje£t of thefe pages to illuftrate, will be found between twenty-nine and thirty-two de- grees twenty-eight minutes north latitude, and twelve and fourteen degrees weft longitude, from the city of Wafhington, and includes what is called the Natches, the country of the Lower Chactaws, a part of Weft Florida, and a confiderable portion of Lower Lou- ifiana. From the mouth of the Ohio to that of the Ya- zow river, in latitude thirty-two degrees twenty-eight minutes north, the inundated country on the Miffiffippi is little varied by high lands, except at the Iron Banks, and Chickafaw Bluffs; generally preferving a width of about fixty miles: but at thefe places, particularly the latter, it is contracted to half its ufual width. The high country, inhabited by the Chactaws, on the eaft 12 fide of the river, projects in at the laft named place, and has its fhores for many miles laved by the impe- tuous current of the Miffiffippi. To a perfon defend- ing that river, the majeftick rudenefs of thefe hills breaking fuddenly on his fight, after having been accuftomed to fee nothing but one uniform flat wil- dernefs, grown over with cyprefs, and brakes of the arundo gigantea, is truly pleafing. Added to this, the depreffion to which he is fubjecf. from an appre- henfion that he is going to an unhealthy climate, his folitary mode of travelling, together with the gloom which the atmofphere of this valley naturally induces, prepare him well to relifli the variety which it affords. Indeed, it might almoft be faid,that his feelings on this occafion, are not diffimilar to thofe that agitated the breaft of the immortal Columbus, when he viewed a new world. The elevated country on the eaft fide of the river, at this place, is extremely poor, producing only a few plants and thofe of a very arid complexion, fuch as the quercus alba, fideroxylon, rhus, fmilax, bryonia, rubus, &c. But on the weft fide, nothing can be more ftrikingly oppofite than the character which the face of the country affumes. After paffing the valley, we come into a moderately elevated country, well watered, of a rich black foil, abounding in a great variety of vegetables ; fuch as the quercus rubra, quercus tin&oria, quercus alba, morus, ulmus, fraxi- nus, ariftolochia frutefcens, tilea, cornus florida, betula nigra, angelica lucida, juglans nigra, jnglans alba, 13 juglans hickory, acer ftriatum, acer rubrum, conva- laria majalis, ftyrax, viburnum, ftaphylea, panax, acer faccharum, &c* It would appear that the Miffiffippi at this place, not only forms a boundary in point of foil; but is alfo a great line between a different zone of vegetables. The country which we mentioned on the eaft fide of the river, extends as far as the upper branches of the Tombigby, pretty uniformly compofed of a tough clayey foil, interfperfed, occafionally, with ftrips of good land, on the banks of fome of the larger ftreams; and free from moraffes in its whole extent. Continuing fquth, the fame character will apply to all the country between a parallel line drawn forty miles eaft from the Miffiffippi,.and another twenty miles weft from the Tombigby river, as far as the head waters of the Yazow, where the foil (with the ex- ception of perhaps about one hundred miles in length, and thirty in breadth, which is extremely fertile, and fwelled into healthful irregularities) changes its clayey complexion for one that is poor and fandy; pr.eferving the fame barren appearance all the way to the fettle- ments on the Pearl river. An extent in width, from * Captain Recce, an intelligent Savage, who had frequently travelled on the west side of t\ e Mississippi, from the mouth of the Missouri to the Apelusaus, informed me, that in all hisperigrinations to the southward, this was the last place he had ever seen the white walnut or sugar tree. 14 eaft to weft, of near two hundred miles, and in length, from north to fouth, of about three degrees. From what is called the Walnut Hills (a fhort diftance below the mouth of the Yazow river, which we have made our northern boundary) to Baton Rouge, about one hundred and fifty miles above New Orleans, in keeping the courfe of the Miffiffippi, the hills, every ten or fifteen miles, recede from our view, affording extents of drowned country at the feafons of high water: and in many places, in more elevated fituations, large lakes, fupplied with water from fprings that burft forth at the bafe of thefe hills, by which they are kept cool and limpid throughout the fummer. This interval between the river and high land, where there are no lakes, is generally grown over with the following trees and plants, viz. cupreffus, po- pulus, juglans pecan, quercus phellos, fambucus, fraxjnus, acer rubrum, ac. glaucum, ac. negundo, feveral fpecies of iris, palmetto, feveral fpecies of ama- rillis and lilium, willow, and near the#borders of the lakes and banks of the river, impenetrable brakes of the arundo gigantea. At Baton Rouge, on both fides of the river, the face of the country affumes one uniform champaign appearance, the higheft part of the earth being that dire&ly on the banks of the river; fo that when the river is fwelied by the fpring floods beyond its banks, the water, which efcapes in this way, never gets back 15 to its parent ftream; but difcharges itfelf on the weft into the bay of St. Bernard, and on the eaft into lake Ponchantran and the bay of Penfacola. However, the quantity which paffes by thefe routs is much lefs now than it formerly was; on account of the embankments which the inhabitants have thrown up to protecr. their farms from the encroachments of the floods. A circum- ftance much to be lamented by the fucceeding gene- rations that are to inhabit thefe fliores, at fome remote future period; for, doubtlefs, had thefe embankments never been thrown up, and the river fuffered to continue its progrefs of inundation and depofition, in a few centuries a fufficient quantity of acreted fedi- ment would have been accumulated to have elevated the adjacent country beyond the reach of inundation; and a few years of vegetation would have been ade- quate to render it dry and healthful. But the prefent method which is pracfifed of reftraining it within its banks, appears to involve confequences fufficiently powerful to break the fhackles which the Louifianians impofe at the expenfe of the lives and happinefs of fo many of Africa's injured fons, and once more emanci- pate this great river from the control of its prefent mafters. Is it not reafonable to fuppofe, that the bed of the river muft become more filled than it otherwife would, were its waters and fediment fnffefed to efcape; and that in time thefe banks will, though annually increafed, be infufficient to withftand the fuperiour preffure of the water, and that nature will accomplifh by her means what the Louifianians have fo long becai driving to execute by artificial ? Nor do I conceive 16 this period of change fo remotely diftant, when I take into view fome phenomena which have come under my obfervation fince my refidence in that country, together with others that have been related to me by gentlemen whofe veracity I would be forry to doubt. In many places, the trees, inftead of having their roots vifibly diverging from their trunks, have them lo buried in the earth, that they look like pofts that have been driven into the ground by fome powerful engine; and, in fome of them, where accidental breaches in the banks of the river have expofed their roots, we can mark the extent of fediment accumulated bv each year's inundation, from.diftincl: fets of hori- zontal roots that burft from little fiffures in their bark at regular diftances, one above another. The diftance between thefe roots differs in different fituations, but in low fituations I think about three inches might be eftimated as the mean ftandard. From counting the feveral fets of thefe roots, in one or two trees, I con- cluded,, that the fhort period of twenty-five years was fufficient to produce fix feet of ground. It will, perhaps, be faid, that my geological in- ferences have been drawn from too flender premifes, and that the lartvs which govern vegetables are too fortuitous in their iffue, to afford data fufficiently de- terminate for our application in accounting for pheno- mena fo thickly enveloped in the mifts of time. My anfwer is, that St. Pierre* was not afhamed to enu- * St. Pierre's Studies of Nature. 17 merate trees among our beft avenues to chronolo- gical truth, and that the corrufcating rays of Darwin's genius have illuminated the fubje£t of vegetation too profufely for us to rank them any longer among the fenfelefs children of blind Nature's operations; but has affigned them to their proper place on the fcale of creation, and has taught the lords of the univerfe to know that they are more clofely allied to the humble vegetable than their ambition is wont to acknowledge. Darwin's genius, by inveftigating their economy, has placed them among the capax rationis;* and Lavoifier has proven, that the vital principle in them depends on the fame fet of agents that give birth to it in the more elevated orders of animated nature. " Organization, fenfation, fpontaneous motion, and life, exift only at the furface of the earth, and in places expofed to light. We might affirm, that the flame of Prometheus's torch was the expreffion of a philofophical truth which did not efcape the ancients. Without light, nature was lifelefs, inanimate, and dead. A benevolent God, by producing light, has fpread organization, fenfation, and thought over the furface of the earth." Twenty or thirty years ago, the lakes between Baton Rouge and the Natches were fo intimately connected with each other, that the people ufed, in order to avoid the impetuous current of the Miffiffippi, to pafs with their large, row-boats from one to the other with facility; but now it would be impracticable, • Darwin's Botanic Garden. C 18 even with thefmalleft cyprefs canoe; and many places that were once the aqueous apartments of the fportive trout, dreffed with gaudy hangings of the nymphsea nelumbo, are now become the habitations of different kinds of foreft trees, and fo perfectly free from moif- ture, that the traveller finds himfelf little incommoded in paffing thefe infant traces of country. Baton Rouge, the Iaft place at which we fee high land, in defcending the Miffiffippi, muft, I think, ori- ginally have been the confines of the Mexican Gulf; for, if here we preferve an eaft courfe, we pretty ge- nerally find the fame appearance in the complexion of the earth and its productions, that are to be met with at the entrance of lake Ponchantrain into the gulf; and I am inclined to believe, that the Amite, which now difembogues into lake Maurepas, about fifty miles below its confluence with the Iber Ville Bayau, origi- nally had its mouth fomewhere about the place where it now meets the Iber Ville, and not more than ten miles from the Miffiffippi. Nothing can exceed the drearinefs of the country through which the Amite paffes after its junction with the Iber Ville, or Bayau Manchac. Qbftru&ed from difgorging its contents into the Maurepas by the fwellings of that lake, which are frequent, fituated as it is, with only the intervention of lake Ponchantrain between it and the gulf. The land is fo low, and extremely level, that the fmalleft fwell in any of thefe lakes, is fufficient tocaufe the water of thefe fmall ftreams to regurgitate; and it frequently happens that the water of Amite is many weeks rifmg to a height great enough to force its way out into 19 the Maurepas; during which time it inundates a very large traft of country. The frequent alternations which ' the earth and vegetables undergo at this place, in paff- ingfrom a moid, to a dry ftate, render it one of the great- elf laboraroriesof noxious effluvia any whereon the Mif- fiffippi. Certain it is, that it is more uniform the year round; for it continues to produce its effects long after the common caufes in other fituations have ceafed to exift. As the object of thefe pages is neither to inftrucl: the geographer, nor arriufe the traveller, but for the perufal of the pathologift, I will quit the banks of the Miffiffippi, and penetrate the interiour of the country 5 with a view of developing fuch of its features as can, in a medical confideration, influence the falubrity of its atmofphere, without having any regard to minute geographical defcription. A chain of hills, fix or feven miles in width, and near two hundred miles in length, extends the whole diftance between the mouth of the Yazow river and Baton Rouge, immediately in contact with the valley of the great river on the eaftern fide. They are of iinmenfe irregularity, and clad in fuch impenetrable brakes of the arundo gigantea, that they are almoft inacceffible with man's moft fertile inventions. The cane here, inftend of being what Virgil has defcribed, Hie virides tenera pnetexit avundine ripas Mincius,.............................................. arrogates fome of the prerogatives of the more (lately 20 inhabitants of the forefts. As if confciotis of its fuper- natural ftature and thicknefs, it here ufurps the fove- reignty, denying refidence to all other citizens of the vegetable republick; but a few towering magnolias, the liriodendron tulipifera, juglans nigra, laurus faf- fafras, and, rarely, a folitary cotton tree, that on filken pinions, while in embryo, has ftrayed from the aqueous region that ftimulated the paflions of its parents to imbue it with vitality, and has fettled here among ftrangers. Like Proteus's herds it has come here vifere monies. On the eaftern fide of thefe hills, their declivity is fo extremely gradual, that, in travelling over them, we are infenfible of the place of their termination. From giddy heights and deep hollows the face of the country is infenfibly tranfmuted into a fertile plain, from fifteen to twenty miles in width; interfered with fmall ftreams of limpid water, rolling over beds of black fand, and meandering through rich forefts, until they find fome chafm in the hills by which they dis- charge themfelves into the Miffiffippi. This beautiful. plain, of at leaft two hundred miles in length from north to fourh, abounds in a great variety of trees, among which are the following, viz. liriodendron tu- lipifera, gleditfia, morus, feveral fpecies of ulmus and fraxinus, magnolia grandiflora, mag. auriculata, lau- rus faffafras, 1. borbonia, juglans nigra, jug. hickory, fagus fylvatica, quercus nigra, q. rubra, q. alba, fagus caftanea, and among the more humble kind the cornus florida, carica, feveral fpecies of adeulus and ilex, rhus, 21 ftderoxylon, fambucus, prunus alba, p. rubra, &c This beautiful affemblage of trees is dreffed out with feftoons of different kinds of vitis, and wreaths of di- ferent fpecies of climbing plants, fuch as the bignonia radicans, fmilax, bryonia, feveral fpecies of patfiflora, baftard foxglove, yellow jafmine, &c. The happy climate which prevails throughout this delicious valley, added to the prolifick quality of itsfoil, renders it perhaps one of the moft defirable fpots in North America. There are few tropical plants that could not find an afylum in this hofpitable fnuation; and daily experience proves, that plants which have been brought here from more northern countries thrive with luxuriance. As it may not be uninterefting I will enumerate a few fuch as are commonly cultiva- ted in their gardens, viz. anguria, pepo, capficum, mala aurea, afparagus, rapum, daucus, mentha, melo, cucumis, braffica coleflora, cynara, paftinaca, braffica capitata, lactuca, fpinachia, beta, nafturtium, cepa, apiumdulce, raphanus, alium,porrum,pifum,cydonia, malus, pyrus, aurantium, ficus nigra, fragaria, &c. After we leave this valley, continuing eaft, the foil grows poorer, and the country fpmewhat more elevated, though not fo much fo as to give it a hilly appearance, until we meet with the open pine lands; where it affumes a character which it afterwards pre- ferves for a width of near two hundred miles. Gently fwelling fand plains, thinly covered with the pinus tseda, p. lutea, occafionally interrupted with copies of 22 the cornus florida, aefculus flava, pyrus coronara, with quantities of the vitis campeftris, that attach them- felves to their trunks and branches; and here and there a folitary horfe chefnut, in places where the foil lofes its fandy complexion, remote from the large favannas, and on the borders of the ftreams which wind through thefe gently fwelling fand knolls. As we approach the Tombigby river, or bay of Mobille, the country becomes more hilly, and the land richer; producing extenfive forefts of juglans hickory, fraxinus, nyffa fylvatica, cornus florida, mag- nolia grandiflora, quercus nigra, juglans nigra, quer- cus femper virens, flammula rubra, myrica, and, until we reach the river, when we once more meet with fwamps covered with the cupreffus, populus deltoides, acer, and bordered round with the arundo gigantea. This obfervation will apply more efpecially to the weft fide of the bay and river, the eaft being either fand plains, or, immediately contiguous to the bay, extenfive fait marfhes. A chain of iflands, between twenty and twenty-five miles in length, and five or fix in breadth, lie in the Tombigby river, above where it expands into what afterwards takes the name of Mobille Bay; which, for feveral months in the beginning of the warm feafon, are inundated by the frefhes in that river. The country between the town of Mobille and lake Ponchantrain, keeping the courfe of the gulf, for a width of thirty or forty miles, is uniformly level anddryj 23 interfered with a few fmall rivers that never overflow their banks. The whole fpace between thefe two places may be called an extenfive fand plain. The only interruption to its champaign character is in one or two places almoft contiguous to the gulf, where we meet withfomecurious moundsof oyfterfhells,of a very Angular appearance. Some of them cover more than an acre in circumference; and are from fifty to fixty feet in height. When they are denudated of a black mould, of from fix inches to one foot deep, which pro- duces feveral kinds of fmall trees, fuch as the cornus florida, prunus alba, myrica, &c. The fhells look as frefh as if they had not been there more than one or two years; and are fo free from any kind of foreign matter, that the people of Mobille and New Orleans convert them into excellent lime, by only making fmall excavations in thefe banks, and placing fire in them. I have often, when looking at thefe mounds, been reminded of Offian's feafts of fhells. I can never be- lieve they were thrown up here by accidental means; but have thought it more probable that they have been carried here by fome of the nations of men that once inhabited thefe fhores. When, perhaps, their religion had the building up of mounds as one of its rituals; or, what is ftill more reafonable, it was then their cuftom, when meeting in. large bodies, for the purpofes of war, or the more pacifick measures of their favage cabinets, to repair to the confines of the Mexican gulf, to make its flielly and finny inhabitants tributary to their wants at this interesting period; and that each of thefe mounds has been the receptacle for the feaftings of a whole nation. 24 METEOROLOGICAL OBSERVATIONS. AS the ftate of the weather may be confidered as the moft important of all agents in its influence over the difeafes of a country, it will be proper for me, previous to my faying any thing of the difeafes themfelves, to make a few remarks on that fubject. The barometer at any time, and at any place in all this extenfive tract of country, feldom rifes higher than thirty inches forty-three lines, or falls lower than twenty-nine thirty-eight. The thermometer, con- trary to what we would expect in a country like this, without any important hills in its whole extent, and in fo low a latitude, is fubjecl: to very confiderable viciffitudes. In January it librates between........21 & 68 February...................................25 - j$ March.......................................28 - 77 April..........................................43 . 85 May............................................60 - 90 June...........................................62 - 97 JulY..........................................63 - 99 Auguft......................................70 . IOO Sepfember...............................6"0 . gr October.................................35 . 87 November.................................28 - 80 December...............................18 - 75 The only places that appear to have any confider- able influence in altering the ftate of the mercury 25 from what might be eftimated its main ftandard, are thofe on the banks of the Miffiffippi, where I am authorized to fay I have generally feen it much lower than in interiour fituations, the moft elevated not excepted. Where the fea-breeze prevails, we find little difficulty in accounting for this difference: but in fituations remote from its influence, as on the banks of the Miffiffippi, four or five hundred miles from the fea, the folution of the phenomenon becomes more difficult—I would attempt its explanation in this way. —The Miffiffippi originating in fuch northern lati- tudes, and rolling down fuch a depth of water, re- quires fo great a length of time to become equalized to the temperature of the countries through which it paffes, that it muft abforb a great deal of the circum- ambient caloric. Thus, at Natchez, even as late as the autumnal equinox, we find many portions of the Miffiffippi water much lower in temperature than that taken from fmall rivers in the neighbourhood of this place; a drcumftance of which the boat-men on this river often avail themfelves in the hotteft weather, when they are in the habit of letting down fome hea- vy veffel to the bottom of the river, to procure water of a low temperature for the purpofe of mixing with their tqffia. We are not furprifed at this being the cafe, when we take into view the great opacity of the Miffiffippi water, owing to the immenfe quanti- ties of fand fufpended in it, which, by obftructing the folar rays in their paffage through that fluid, and thus making the evaporatory procefs commence near D 26 the furface, prevents the equalization of temperature, being as uniform as it otherwife would. Another circumftance which we muft take into con- fideration, is theimmenfe quantities of caloric rendered latent in waters paffing from the aqueous to the sere- form ftate. As the fpecifick gravity of air impregna- ted with water is much lefs than pure air, a vertical motion, or rifing up of this aqueous air, and a rufhing in of more denfe air to fill up the vacuum, will be continually going on; and thus a large quantity of heat abftracted from the adjacent atmofphere. This obfervation receives confiderable confirmation from fituations fuch as have been mentioned enjoying more uniform breezes than other fituations lefs contiguous to the river. In travelling on the banks of the Mif- fiffippi in places where it is inhabited, the fmoke from the different plantations will be feen uniformly in a calm day inclining toward the river. How fhall we account for this phenomenon, unlefs we attribute it to the air rufhing in to reftore the denfity of the atmof- phere at that place where the continual procefs of rarifaction, by the means of humidity, is going on ? Certainly it cannot depend on any fpecifick attraction between carbonick gas, and on the hydrogen and oxygen of water. We are aware here that thefuperiour gravity of carbonick air, would naturally difpofe it to feek the loweft fituations; but on the river this is not the cafe. Many fituations back are much lower; and from Ba- ton Rouge to the fea it is uniformly the cafe, that 27 the farther you recede from the Miffiffippi the lower the country becomes. I am indebted to William Dumbar, Efq. of the Miffiffippi Territory, for the following obfervations. The winds of this country, in the winter feafon, are extremely variable, feldom blowing three days fucceffively from the fame point. The north-weft winds bring us the fevereft cold. It may be confidered as a general rule, that all winds during winter, blow- ing from the eaft of the meridian, bring rain, and thofe from the weft, dry weather. 1 he eaft and fouth-eaft winds are not abundantly charged with moifture, as the oppofite points are always the drieft. The north- eaft, during this feafon, are moft difagreeable, but fel- dom prevail for any length of time. The north wind brings (though rarely) fleet or fnow. After three or four days damp, cloudy, and rainy weather, it fuddenly clears up with a cold north-weft wind, which blows frequently with great force during the firft, and fometimes the fecond day of the change ; the night being generally calm. Afttr a like period of clear weather, of which the two firft days are clear and freezing, and the other two fine, mild, and agree- able, with a morning's hoar froft, it revolves into the fame circle of damp and rainy weather. This, with fome exceptions, may be confidered the general cha- racter of our winter feafon. As the fpring and fummer advance, the winds blow chiefly from between fouth-eaft and fouth-weft, 28 with frequent variations from all points of the compafs. During the hot feafon, the winds are frequently re- marked to follow the progrefs of the fun ; being found at north-eaft in the morning, and, fhifting round, die away in the evening at South S. Weft. The fummer evenings are generally ftill until between eight and nine o'clock, when a fine cool zephyr from the weft or fouth-weft fets in. The months of June and July compofe the hotteft part of the year. Daily refrefh- ing fhowers of rain begin and continue throughout Auguft, which diminifh the exceffive degree of heat that otherwife would prevail at this feafon. The wea- ther continues fhowery through September, it fettles fair, and there is.yearly, almoft without exception, fix or feven weeks of the moft delightful feafon imagin- able. Pluviometrical regifters prove, that our greateft fall of rain is in April, September, July, May, and February; and in point of quantity in each month nearly in the order they have been enumerated. The quantity which falls in a whole year, is fomewhere about thirty-five inches. 29 MEDICAL REMARKS. IT is generally not until the middle or latter end of June that the pepple fettled on the Miffiffippi and Tombigby rivers begin to be vifited by difeafe. The waters of thefe rivers, which had been rifing for three or four months, now begin to recede from the face of • the country, leaving huge furfaces of mud and water expofed to the influence of the folar heat which occa- sions an immenfe decompofition of water and vegetable fubftances, and confequently, a copious rmiffion of a gas compofed of fome of the component principles of thefe articles. Some experiments performed on what I prefume was a fimilar air gave the following refults. Having obtained in two feparate bottles, in each above a pint of the air from the bottom of the Schuyl- kill, and from a marfh adjoining, it was fubjeaed to the following tefts to afcertain its nature. FIRST BOTTLE. Experiment I. A meafure of the air was thrown over lime water in an eudeometer, which did not make it turbid. Experiment II. A meafure of pure nitrous air, obtained from the aaion of the nitrick acid on copper, being added to one meafure of the air in the eude- ometer, produced no abforption. 30 Experiment III. An ounce meafure of oxygen air added to two of this air in the eudeometer of Vol- ta could not be exploded by the ele&rick fpark. But upon adding a fecond meafure of oxygen, the explo- fion was very loud, and one meafure and a half dif- appeared. The air left in the eudeometer was found to contain carbonick acid, which was proved by paff- ing one hundred parts through lime water, which was rendered turbid, and twelve and a half parts were abforbed, giving the quantity of the carbonick acid. After this laft experiment the remaining air was highly inflammable, burning for a confiderable time. SECOND BOTTLE. The air in this bottle was found a little different from the firft, being collected in another place, a little diftance off. The firft and fecond experiments turned out as before; fo did the third. Experiment IV. Two meafures of oxygen and two of the air being put into the eudeometer of Volta, being fired by the ele&rick fpark, only half a meafure was abforbed, with a lefs explofion than.before. Experiment V. To two meafures of the air were added two and a half of oxygen. As before, they now exploded by the fpark violently, and one and a half meafures were abforbed. The portion of carbonick acid was the twenty-fifth part; the remainder ftill burning as at firft, i. e. before any experiments were made. 31 It is not my intention, in this place, to enter upon an inquiry into the relation which marfh effluvia bear to the health of the inhabitants of places where it abounds. So many gentlemen have wreathed their brows with the laurels of ingenuity, by volunteering their fervices in this gafeous inveftigation, that the fimple enumeration of their feveral names, would be exceeding the limits which time has prefcribed to this effay. Yet had it been within my power to give an analyfis of the atmofphere of this country, I certainly would have done it; as it doubtlefs would be an im- portant confideration in the pathology of its difeafes; efpecially at this enlightened era in fcience,—when the torch of Philofophy, guided by the hand of Chy- miftry, is illuminating the moft intricate arcana of na- ture, in fpite of the maffy barriers erected by ages of fuperftuion and ignorance. The low temperature of our nights in May, June, July, and Auguft, owing to heavy dews, together with, perhaps, the want of a fufficient quantity of oxygen in the atmofphere, owing to the great admixture of hydro carbonick air with it, accumulates fuch afurface of excitability, and the ftimulus of the folar heat du- ring the day is fo exceffive, that the fanguiferous fyftem, unable any longer to refift, begins to take an unhealthy action, evincing its morbid appearances gene- rally in fome of the following forms, viz.—Intermit- tent, mild remittent, and yellow remittent fevers, cholera, diarrhoea, dyfenteria, hepatitis, fplenitis, or tumor-fplenis, urticaria, phrenitis, eryfepelas, op- 32 thalmia, icterus, and different kinds of hydropick af- fections. In October, the yellow remittent fever, which is frequently epidemick in fome of our moft unhealthy fituations (fuch as New Orleans) during the fummer, now begins to difappear; and the only difeafes to be met withare, mild remittents, dyfenteries, obftructions of the chylopoetic viscera, and a few intermittents. But by no means in the proportion that has hitherto been fuppofed. While in the fervice of the United States, I kept a regifter of the fick at head-quarters, Mulberry Vale, five miles eaft of the Miffiffippi, and, as well as I am able to recollect at prefent, out of three hundred men whofe health I had under my care during the fummer and fall, there never were more than ten cafes of intermittents, in one day's re- port, while the number of remittents have often amounted to more than fifty. Thofe who have fuffered from the difeafes of the warm feafon, by the middle of November, from the fine weather which prevails at this feafon, be- gin to regain their ftrength, and ufual vivacity; and from this time until the firft of May, the people of this country enjoy as good health as per- haps any of their more northern neighbours. Added to a more moderate climate during this period, their fyftems have the advantage of being worn down to a reduced ftate of excitability, which enables them to refift the morbid tendency of the few catarrhal affec- 33 tions which occafionally appear at this time. Thus it is a rare occurrence for a cynanche to become danger-, ous; or for a pneumonia to terminate jn either vomica pulmonum, phthifis, or death. Original .typhus I be-> lieve, has feldom or never appeared, among us; and the few cafes of typhus which I have feen have always: fucceeded neglected or ill treated yellow remittent. fever, pneumonia. Podagra and rheumatifms are al- moft unknown among us. Even the foldiers of the firft, fecond, third, and fourth regiments, who had ferved under generals St. Clair, Harmer, and the immortal Wayne, in their feveral campaigns carried on againft the favages in the inhcrfpitable climate of the lakes and North-weftern Territory, have fince their arrival in this country become quite free from any rheumatick affection. Notwithftanding that, ma- ny of them when they firft landed at the Natchez were fo ill with it, they were unable to perform the ordinary duties of camp. To the difeafes that have been mentioned as be- ing peculiar to this country, we may add a few others which obferve no particular feafons of approach, viz. diabetes, tetanus, frambcefia, lepra, and trifmus naf- centium. This laft complaint is very common in the low country from Baton Rouge to the fea, infomuch that it is a very difficult thing for the planters to raife young negroes : and notwithftanding that they take the precaution of always giving them fome mild cathartick fhortly after birth, at leaft five eighths of all that are born die of this complaint within the firft 34 two weeks after birth. That the children of this part of the country mould be fo fubjedt to this difeafe while thofe of Natches and New Telleciana irnmcdL atety adjoining, are free from it, is curious. With Dr. Mofeley, I would attribute it to the greater inhu- manity of the Spanifh and French planters exercifed over the parents of thefe unfortunate children, and to the want of proper attention in the nurfmg of the child itfelf. finis. P397p 1203 M ' 3 .2''...■ :'Vr .^.\v^:>>vii'^v:r:*:;i&v."5!)-:ir::cjj^(>: P if,.. <"A\>