enough to think that such an Italian substance as malaria can exist in the centre of the English capital." 101. Dr. M. remarks, that " to prove that mill-dams, though transmitting large streams, ought to be injurious, from the frequently marshy nature of their margins, would be to repeat what has been said before, respecting the priori proofs on this subject in general." About the iron district of Glamorganshire, he informs us, there are numerous large mill-dams for the supply of machinery; " and there is not one of these, in the lower grounds, which is not notoriously attended by the endemic illhealth of all the immediate residents and visitants, consisting in the diseases already mentioned." Of these, neuralgia, he states, is a very common form. These local exceptions to the general health of the surrounding hills and dry places, are peculiarly remarkable, and have attracted the attention of the inhabitants themselves. As it is incumbent on medical men to attend to medical topography, and thus to put the doctrines of our author to the test of experience, we shall dwell more on localities than we otherwise would have done, in order to excite the attention of our readers to this important subject of investigation. A milldam, he says, at Southend, near Lewisham, affords a striking example, though on a small scale, while it is also an instance applicable to fish ponds, and other kinds of still water similarly circumstanced, "Here the poorer inhabitants in particular, are notedly subject to intermittent as well as autumnal fever, while they bear marks of glandular visceral affections, and are reported to die of the consequences of those disorders. To have seen the fit of intermittent invariably produced in a susceptible individual by an approach to this pond, hundreds of times, and always within a stated distance of time from the approximation, completes an evidence which cannot be controverted." 105. In farther illustration, Dr. M. instances the valley of the Ravensburn, with the communicating low lands, including the villages of Lee and Lewisham. There is a peculiar physiog nomy, he remarks, attached to all such places, which renders it easy to distinguish them. " I may here add another instance, from the mill dam of a paper mill in Hertfordshire; after the formation of which, the workmen became subject, in a most serious degree, to remittent fevers, which were, before that, unknown, and as the ground in this particular instance resembled that of an ornamental park, as did the water itself, it may suffice to prove what I have advanced on that particular subject; although it would be easy to confirm this by analogous instances adduced from many of the dressed pleasure grounds orna mented by water, which skirt the Thames, near Walton and Chertsey, and which occur also in a hundred other places: the produce of a well known improving gardener, or else of his progeny; to the demerits of whom, as the sources of an endemic disease of English landscape, far, very far yet from being extirpated, an eruptive contagion blotting our fair island, it is no small addition that they have, in founding ponds which their vanity mistook for rivers, and in converting rivers into Dutch canals, brought the intermittent to our doors under cover of the breeze of the violet, and formed pest houses of fever where we study to retire for coolness from the heats of the autumn. This is to manufacture a Batavia, in defiance of nature; to court disease through deformity and expense; the evil less, it is true, but of the same kind, and incurred as certainly." 106. The above is another fair specimen of the style and manner of our author, where he aims at being peculiarly impressive through the medium of unconscionable sentences-a single one of which just occupies a page of the original work in the foregoing quotation. Dr. M. here instances a spot in a high, and formerly healthy part of Hampshire, where a clear and quick stream was dammed up, not long ago, for ornament and use. The immediate con sequence was, the production of evening mists, before unknown -and the result was, autumnal fevers. Dr. M. never lets an opportunity slip of levelling a sarcasm at the country apothecary, though a better acquaintance with that class of medical practitioners would have taught him, that they think just as much as, and probably more than, their brethren in towns and cities. "A French or an Italian physician would be at no loss here in deciding; but the English apothecary, having no term but typhus for a destructive fever, decides accordingly; never questioning himself as to the origin of the contagion of which he dreams, nor ever recollecting to wonder why it should not spread to the attendants, when the patient is covered with petechia; and thus the public goes on creating more mill-dams, more fish-ponds, more fictitious rivers, and, after the models of Brown, more fevers." 107. We are not among those who flatter, for base purposes, one class of the profession at the expense of another. There is a mixture of ignorance and intelligence in every class—and all sweeping conclusions, that would represent one class as dolts and another as angels, are necessarily unjust, as well as ungen erous. Here our author quotes an instance, (doubtless in his own person) where the recurrence of an intermittent fever, in a susceptible subject, was caused repeatedly, "by merely entering a VOL. VIII. No. 15. wing a pond of the fashion of King William's aqua fishes and river gods.” are degree of delicate susceptibility, Dr. M. table miasmometer, and as such, might ce the government, as well as to famine saibrity or insalubrity of various localselected for public establishments or Dr M relates another instance, which There was a small pond occupying be common, close to a house belonging and occupied by General Stebelin gbt a few square yards. It was Surse of years, that the inhabitants may harassed with agues; and was destroyed by improvements sease disappeared-for ever. Dr. ccurrence of ill health, in numeraves pts of commons are filled with th's very cause; and that, in Juu London, &c. so often selected for nur gravelly soils, “are very genyoued causes of ill health.” What estants of Putney-heath, Wimbledon, There is no doubt, however, gus have actually shown themselves nen the said complaints have preEngland, and in almost every street mething more, in our humble opinion, Caying vegetables to be taken into .. production of epidemics. We apwas not far wrong, when he suspected springing from "the bowels of the e no doubt that the causes forming Con in this Essay, do ordinarily work r. Macculle is unquestionable. Volney, Nash, and fifty other authorities, might be cited in proof. Why this should be the fact, if it cannot be very precisely explained, is not at least more difficult than most of what else belongs to this subject; since there is a quantity of vegetable matter killed, and therefore submitted to decomposition; and it would be well worth the trouble of those whose local situations give them the means, to inquire whether this, and many other analogous agricultural processes, now little suspected, are not the causes of the fevers which sometimes appear in rural situations in such an inexplicable manner, when these cannot be better accounted for by stagnant waters of various kinds, or by such neglected spots as I have here been pointing out. The remark is of value, be the solution what it may; because the remedy will be found in breaking up such lands in June, or in May, if the summer be the necessary period, or, what is preferable, in the middle of winter; since the decomposition will then take place at a time in which experience has shown that Malaria is scarcely generated in our own country, nor indeed, generally, in Europe. In the case of lands recently recovered by drainage, this precaution is peculiarly deserving of attention, because in this case the danger is greatest; and the same is equally true of woods, the mere felling of which sometimes disengages or produces Malaria, as is a much more certain consequence where, as in America, and as I have elsewhere noticed, these woods are broken up for cultivation." 113. The same observation applies to drainage as to tillage. A swamp may be too wet to produce miasmata-and a certain drainage may just bring it into that state which is peculiarly favourable for the extrication of the unknown poison. This appears to have been the case with the Campagna di Roma, as far as the facts can be ascertained by comparing the different accounts of Italian writers. The most pointed instance, however, is that of the marsh of Chartreuse, near Bourdeaux. A succession of bad fevers, before unknown, showed themselves immediately after the drainage of the above marsh, first in that part of Bourdeaux which lay nearest to the land reformed, and afterwards through the whole of the town. These fevers lasted for many years, and proved so severe in 1805, that 12000 people were affected, three thousand of whom died in five months! quest** "It is not difficult to understand that a swamp in which the water is so deep as to impede the growth of as many plants as a drier surface uld carry, will produce proportionally less of the poison in and that a similar diminution or under proportion of Mafend such a tract of land if it should contain many divested of all vegetation. In such a case, we can ain state of drainage, such as to increase the vege without being at the same time complete enough to "Could this admit of doubt, or could those who have made no observations, or who are incapable of observing, choose to deny the well-known facts now alluded to as evidence, it would be proved by the great distance to which Malaria travels through the air without losing its poisonous quality. Not to dwell here on examples which must be adduced hereafter, it is quite familiar that from any known and often very limited spot, this poison will proceed through the air, or on the winds, to distances of three or four miles, exciting as much virulence as in its native marsh. This, to quote a familiar domestic example out of hundreds that might be adduced, occurs on the hills of Kent, far from the marshes of Erith, Northfleet, or Gravesend; and it is easy to see that whatever was the body or quantity of Malaria in the original place of its production, or whatever portion of atmosphere it occupied over the few acres by which it was produced, it must often, in such a course, have been diluted to a degree so incomprehensible, that while we can only wonder how it should exist at all as a distinct substance, or a chemical compound, even more must we be surprised that it should be capable of producing its peculiar diseases, with an activity as great, and often greater, than it did at the very point of its birthplace." 55. How does the above comport with the well-known fact that our ships moored close along the banks of the Scheldt entirely escaped the fever, while the soldiers quartered within half a cable's length of them were all affected with the epidemic? The same has been observed in hundreds of other places. We do not say that miasmata are not carried along by the winds; but we do maintain that they are weakened by the dilution, in as nearly a ratio to the distance carried as possible. How is Dr. M certain that the hills of Kent do not generate miasmata, seeing that hills in other parts of the world are not exempt from such productions? Nothing is more common than marshy spots and even stagnant water on the tops or declivities of hills while at their bases, springs of water and plashy grounds are invariably found. The marshes of Erith, Northfleet, and Gravesend, may not then be guilty of producing fevers on the distant hills of Kent. We doubt whether the following conclusions will be admitted by the professional public, although Dr. M. seems convinced that he has reduced them to a kind of arithmetical certainty. "This conclusion is obvious; and there is nothing in it which seems to admit of dispute, since it is almost a question of arithmetic. If the produce of a hundred square feet, or acres, or of any scale and number of parts, can, under a dilution of one thousand or ten thousand times, excite disease, then must, in the inverse ratio, the produce of the one-thousandth or the ten-thousandth portion of that space be capable, before dilution, of producing the same effects; or a single blade of grass acting on water (if this be the cause) may be |