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nations of temperature not only aiding in this way the concentration of the effluvia with moisture, but affecting the constitution by their agitating concussions, and debilitating the frame by the alternate excitement and languor which must end in more or less notable prostration. We would thus also account for the fact, long recorded among planters, that attacks of country-fever are more likely to occur in May than in June, whence many of them have derived the habit of remaining on their plantations until the latter month, changes of place being supposed, whether justly or not we do not pretend to determine, to give additional susceptibility. Warm as is our vernal sun, the nights of May are often cool and refreshing. The winds during that month blow not unfrequently from the eastward, and their chilling impulse is imagined to have a tendency to give effect to the poison which is lurking in the frame of him who has been breathing the contaminated air of his country residence. The difference at this season is, of course, not so open or obvious, as that which exists between midsummer and the late autumnal months, but it is not unknown nor has it passed unobserved. We need hardly remark that the power of Malaria is but feebly developed in early spring, when the frost has not ceased to retard the processes of vegetable decay, and to confine to the earth, at the most dangerous period-night-the moisture which gives activity to the poison. But it is in confirmation of the views stated above, that if in the autumn an early frost occasioned by a premature and hasty north wind, with previous rain, has seduced the inhabitants of our lower country into the Malaria districts, the fevers to which they thus become liable, are particularly severe, obstinate and malignant. We believe that such irregular alternations of temperature, have been more frequent of late, than they were formerly, both in spring and autumn.
But this direct and immediate effect of cold is not all, nor is it, perhaps, even the most important of its agencies in the matter under consideration. The permanent influence of cold upon the human system cannot be exactly described; we call it tonic, constringent, roborant. That of heat is probably directly opposite. Very different then will be the states of the constitution which result from exposure to these two conditions of temperature; very different the predispositions to disease built up in the constitutions so modified. One who has become familiar with the influences of heat, having gone through a regularly progressive series of effects producible by it, directly and indirectly, in warm climates, is said in common language, to be assimilated to such climates; he has become jess liable, generally speaking, to their endemic diseases, than
he was originally. Impressions thus made on the constitution, may, however, be erased; assimilation thus acquired may be absolutely lost by a return to colder regions, and a longer or shorter absence from the scene of the first mentioned changes. The contrasted operation of cold may be undergone, and the susceptibility renewed, which had been impaired or lost. It has been usual with our southern people in reasoning upon this principle, for it is universally recognised and acted on, to regard, as somewhat dangerous to a young native, whose constitution is still plastic and liable to impressions, or to a stranger who has been resident here, the prolonged absence of a summer in a northern region. Now, although we would by no means go so far as to deny the possible influence of a Northern or European summer, for we have more than once had personal occasion to notice it, yet we look upon a winter spent in those climates, as much more impressive in changing the state of a southern or assimilated constitution, than many summers, for the plain reason, that the difference between the warmth of our summers and those of northern countries, even so far as Russia, is infinitely less than the difference between our winters and theirs in severity of cold. It is uncommon in Charleston to see a crust of ice covering a pail of water, which will endure the heat of a single day; at Philadelphia, the great river Delaware is frozen over annually, so as to bear on its surface sleighs and carts, and immense multitudes of people. But it is far from being a rare occurrence, that the extreme summer height of the thermometer in Philadelphia, we might venture to say in Canada, equals its highest range in Charleston. Let us suppose then, that instead of our going abroad to suffer a northern winter, which can happen at once to but few comparatively, a northern winter should come upon us at home. The effect would evidently be the same in both cases precisely-the constitution would lose in a greater or less degree, the protection afforded to it by its previous assimilation, and we should have become to a corresponding extent, strangers. Facts will be found to confirm these views. For instance, our memorable epidemic summer of 1827, found us all, in some measure, strangers, the winter then just past, having been unprecedentedly cold; and the fevers of that spring, though a dry one, and not particularly hot, commenced earlier and with more violence than had ever before been known. Our last winter was, on the contrary, but a genial and mild autumnal season, fruits having ripened during each month even in the open air. Our spring and commencing summer has scarcely shown a case of fever; the very few that have occurred, have been exceedingly mild, and our community has not as yet to
What other in
deplore a single member lost in this manner. fluences may hereafter operate to change the character of our remaining warm months, it would require the spirit of prophecy to point out, yet we are sure of having this in our favour, that we enter upon them with all the callousness which the repetition of impressions can bestow.
We believe further, that it would not be difficult to make good the assertion, that irregularities of temperature have been particularly remarkable within a few years, not only in the southern section of our Union, but over the whole Atlantic coast, and, perhaps, over all the civilized world. For proof of this, we would refer to the steady summer warmth of the winter of 1827-28, both with us and in the northern and middle states, vegetation being scarcely more than checked or retarded, and that, we believe, rather by the habits of plants, to follow the revolutions of the year, than by the absolute influence of cold; to the extreme cold of the preceding winter (1826-27) in these southern regions; to the unheard of rise of the thermometer in the summer of 1826, to 90° of Farenheit, in London and Paris; to a similar extraordinary degree of heat in 1825, in the northern parts of our continent, we, ourselves, having noticed it at 97° in June of that year, at the foot of the Green Mountains of Vermont; and to the heat of 1824, along our sea-coast, and in some interior districts where the thermometer reached 103 and 104°. We need surely adduce no other evidence than this, to prove that some very extensive agencies have been at work to influence of late the regular increments and decrements of the temperature of seasons; and such causes would, according to the opinions we have been advocating, be sufficient to account, in a great part, for the alleged anticipation of the season of Malaria fevers with us. Setting aside all this, however, we should still be able to explain the apparently increased insalubrity of portions of our own country. Partial clearing, by exposing virgin soil; by taking away the shade of trees, and thus admitting the heat of the sun; by the mere removal of the trees themselves; by laying bare the edges and banks of our numerous bays, ponds and swamps, whose margins are naturally sheltered by a thick vegetable fringe-this very line of margin being, on account of the fluctuating quantity of water present, the portion of it most productive of Malaria-partial ditching, by collecting water to stagnate, without conveying it off readily, rapidly and entirely; partial draining, by uncovering in greater or less degree, the foul, fermenting beds of the bays, pools and swamps above-mentioned; partial cultivation, by continually turning up new lands, and leaving the old to produce rank grass
and foul weeds, a process that makes two sources of Malaria for one which nature, not sparing in such matters with us, has spread out-these are the obvious causes of such increased contamination of air as is affirmed to exist.
We will confess ourselves to be among those who look hopefully upon this subject, dark as is the aspect which it presents to us now. Many changes are in progress, whose tendency is ultimately to do away, or at least to diminish indefinitely, the evil of which we complain.
As our population increases, and our cultivation of the soil becomes more perfect, draining will, of course, be more complete; the forests will be cut down; ponds and swamps will be emptied of their water and planted; the whole face of the country will be drier and better ventilated; the loose vegetable surface will gradually decay and disappear, except in certain spots where it is inexhaustible; and manures will be substituted, which are not calculated to give out these noxious exhalations. We see these happy results exhibited in the fens of Lincolnshire in England, in some parts of Lombardy, and, indeed, examples of a similar nature are not wanting in our own country, new as it is. We see the effect of even the partial cultivation already instituted, in the diminution annually to be observed in the amount of water carried down by our branches, creeks and rivers to the ocean, and this diminution must go on in proportion with the exposure to evaporation allowed by the successive fellings of our eternal forests, and the thinning away of the exuberant undergrowth-the curse of our lower country.
A more indirect effect of thus opening the universal face of nature, will be, as it ever has been, an increasing mildness of climate. Something of this kind has long since been observed to be taking place in every part of our continent. Every where the winters are, speaking generally, less severe than in the olden time. Here snow is now seldom seen, not once, perhaps, in many winters; and the merry sleigh bells are not heard for half so long a period, nor with half the constancy with which they sounded along the streets, and roads, and rivers of our northern brethren "sixty years since."
Similar causes will, probably, give rise ultimately also to an equability of climate hitherto unknown; and we have shewn fully our reasons for believing in the highly advantageous influence of regularity of temperature in leaving the constitution the benefit of undiminished assimilation from one season of Malaria to another.
We feel humbly, yet earnestly confident in the truth and soundness of these prospective views, and we are certain that even
the most sceptical of our readers, will join in our ardent wishes and fond anticipations.
It is now time we should return to our author for the civil purpose of bidding him, for the present, farewell. We had, indeed, well nigh forgotten him in our anxious speculations concerning the future prospects of our own fertile plains and happy hill-sides. We cannot part with him without offering him our acknowledgements for his very excellent Essay. We might suggest some alterations in his arrangement, and in the connection and succession of the several branches of his subject, which he seems to us, to have occasionally transposed. But it is beneath the true spirit of useful criticism, to look too narrowly into the slight defects of the manner of a writer who is earnestly, and zealously, and ably engaged in the discussion of a topic of such weighty import. If he shall display, in the two remaining volumes promised us in his preface, the same industry, learning and candour, which are shewn in every part of the treatise already published, we shall not hesitate to pronounce the whole work one of the most valuable additions which, in modern times, has been made to medical literature.
ART. VI.-Recollections of the last ten years passed in occasional residences and journeyings in the Valley of the Mississippi from Pittsburg and the Missouri to the Gulf of Mexico; and from Florida to the Spanish frontier: in a series of Letters to the Rev. James Flint, of Salem, Massachusetts. By TIMOTHY FLINT, Principal of the Seminary of Rapide, Louisiana. Boston. 1826.
FROM the Gulf of Mexico towards the north, through twenty degrees of latitude, lies one of the most interesting sections of the globe. It was discovered or rather visited for the first time by Ferdinand de Soto, about the middle of the sixteenth century. In 1685, a French colony under M. de Salle, attempted to make a settlement on its southern border, but after quarrelling among themselves and putting to death their leader, the whole colony perished, except a miserable remnant that passed up the country and succeeded in reaching Canada. About fifteen years afterwards, another French colony under M. Iber