metrical obfervations, that, during the prevalence of the fuppofed conftriction, the temperature of the body is feveral degrees below the healthy ftandard.

Our author had affirmed that cold ablution, and cold liquors, to a certain quantity, are falutary during the excitement produced by exertion; and moft falutary at the highest point of excitement. He lays it down, as we have already stated, that there is a gradation in the propriety or extent of the practice, depending upon the occafional caufe of the heat-producing action of the capillary veffels. Now, in the cafe of temperature increased by mufcular exertion, will he contend for the precedence or concomitancy of fpafm? Why then should he introduce it into the cafe of temperature increafed by the exciting caufes of fever? Has he not himself warranted us to affume, that we have here only a difference in degree, not a difference in kind?

We must refrain from pufhing thefe interrogations further, in order to notice a remark at the foot of p. 145. It appears to me,' fays our author, that whatever the nature of the vital energy may be, it does not act in a way that admits the relations of quantity to be applied to it.' This, we confefs, paffes our understanding. We cannot conceive how any action or power in nature can be fo circumstanced, as not to admit the relations of quantity to be applied to it.' We may not have a measure for certain actions or powers; but how they can fail to be greater or less, we wish the author to explain, if

he can.

To the facts and reafonings concerning ablution with cold or tepid water, in which many things worthy of notice occur, befide those on which we have touched, are fubjoined two interefting chapters. The first treats of the population of Liverpool, and the prevalence of fever there: the fecond controverts the doctrine of inhalation by the fkin, and is well worth the attention of experimental phyfiologifts.

If the proverb. that one half the world knows not how the other lives, needed confirmation, we know not where ftronger confirmation could be found, than in the former of these two chapters. Who, that has been at any pains to inform himself concerning the great commercial town of Liverpool, has not heard of it's healthiness? It's accommodations for shipping fcarcely ftand higher in the report of fome boafters, than this advantage. Dr. C. quotes from the Liverpool Guide, a paffage, according to which, infectious fevers are never known to prevail.' He himself fays, that the upper claffes of inhabitants are not often fubjected to their ravages, p. 201. But how ftands the fact with regard to the lowest class?-Let our author answer.

P. 202. Of the inhabitants of Liverpool, it is afcertained, that about 7,000 live in cellars under ground, and nearly 9,000 in back houfes, which in general have an imperfect ventilation, efpecially in the new streets on the fouth fide of the town, where a pernicious practice has lately been introduced of building houfes to be let to labourers, in fmall confined courts, which have a communication with the treet by a narrow aperture, but no paffage for the air through them. Among the inhabitants of the cellars, and of thefe back

VOL. XXVIII.

F

houfes,

houfes, the typhus is conftantly prefent, and the number of perfons under this difeafe, that apply for medical affiftance to the charitable inftitutions, the public will be aftonished to hear, exceeds 3,000 annually.'

Some pages lower, we have a tabular view of the fever-cafes on the books of the difpenfary, from 1780 to 1796 inclufive, upon which Dr. C. remarks:

P. 211. Thus it appears, that of 213,305 patients admitted in feventeen years at the difpenfary, 48,367 have laboured under typhus; nearly a fourth of the whole; an immenfe proportion!' B. W.

ART. XII. An Effay on the medicinal Properties of factitious Airs. With an Appendix, on the Nature of Blood. By Tiberius Cavallo, F.R.S. 8vo. 270 pages. Price 5s. in boards. Dilly. 1798.

THE aerial department of medicine has now been cultivated for fome time by intelligent practitioners, but the refults of their trials have not yet fufficiently fhown the powers of the fluids which they have employed, or obviated all the doubts entertained respecting

their use.

The author of the prefent effay therefore modeftly informs us, that,

Pref. r. i. The defire of extricating the fubject from the conflict of contrary opinions, established prejudices, and oppofite interefts, has induced the author, perhaps too haftily, to publish the prefent work, which, in every fenfe of the word, deferves the epithet of imperfect. But he hopes that the importance of an object fo highly interefting to the human fpecies, may palliate, if not justify, the imperfections of the performance, which might, perhaps, have been lefs excufable in other fubjects.

To exhibit a concife view of afcertained facts, to feparate them from fuppofitions and hypothefes, and to point out the ways of inveftigating the farther ule of factitious airs, has been the author's principal aim in the compilation of the prefent effay.'

Though an admirer of the ingenuity, caution, and perfeverance of many of thofe, who have been engaged in exhibiting aerial fluids, the author has here, perhaps, properly avoided complimenting them.

The plan of the effay is this. P. iv. The first four chapters contain fuch facts as may be of theoretical ufe in the applications of aeriform fluids, and in the investigation of their action, independent on medical cafes. The fifth chapter exhibits a concise -view of the modern theory of aerial fluids, and of the procefies that are principally depending thereon, fuch as refpiration, combuftion, &c. The fixth and feventh chapters fhew the practical application of thofe fluids by way of remedies to the human body; and this practice is exemplified in the eighth chapter, in which a felect number of authentic cafes is related. The ninth, or last chapter, contains feveral practical remarks, hints, &c. which could not be conveniently inferted in the preceding part of the work.

6

Laftly, a differtation on the nature and properties of blood has been added by way of appendix, that fluid being evidently and principally concerned in refpisation, and in the general dependance of the animal existence on the aerial fluids.'

Of the ufe of a mixture of old and new chemical terms we cannot approve; it is more likely to create confufion, than to render the author's meaning lefs equivocal, or more generally intelligible. The first two chapters contain an account of the principal properties of fuch airs as have been employed as remedies, and of the circum ftances and phenomena that prefent themselves in breathing oxygen air; but we do not find any addition of new facts, or much novelty in the observations that are made on thofe that have been long known.

The following remarks, contained in the third chapter, it may not be improper to lay before the reader.

P. 41. I would not,' fays Mr. Cavallo, be understood to affert or think that the action of the unrefpirable gaffes confifts merely in lowering the quality of common air, or of oxygen air; for that purpofe could be more commodioufly anfwered by breathing a certain quantity of common air longer than in the ufual way. The fact is, that befides rendering the common or oxygen air lefs refpirable, each particular gas imparts peculiar and remarkable properties to the mixture, which mixtures are of courfe applicable to particular cafes. With refpect to thofe mixtures, much has been already afcertained; but a great deal more. remains to be examined and tried under a variety of circumftances, to which object we must look forward with anxious expectation.'

We here meet with fome other obfervations and cautions that intereft the pneumatic practitioner.

In the detail of facts on the application of elaftic fluids to other parts of the body befide the lungs, we have nothing of any importance that is new.

The fubject of refpiration is equally curious and interefting; and,. although the late difcoveries in chemistry have thrown much light on it, there are ftill many difficulties to be removed. A paffage or two may not be uncntertaining or unuseful.

P. 81. By an eafy application of thofe facts to the phænomena of refpiration, we are led to conclude, firft, that the redness which the blood acquires in the lungs, indicates a real oxygenation of that fluid; fecondly, that the oxygen is flightly attached to the blood, for the blood easily parts with it at the extremities of the arteries; thirdly, that the oxygen, which is depofited by the blood at the extremities of the arteries, enters into combination with, and gives firmnefs and folidity to, thofe particles of matter which give increment and stability to the animal frame; fourthly, and laftly, that as the bond of union between the blood and the oxygen is not very ftrong, and as the union of the oxygen with other fubftances at the extremities of the body is much stronger, therefore it seems evident that the caloric of the oxygen air is not entirely evolved from it in the lungs; but that the greater portion of caloric is evolved at the extremities of the arteries, where the oxygen is more powerfully attracted by other fubftances than it is by the blood in the lungs. Hence it follows, that the origin of animal heat does not exist in the lungs only, but that it takes place, more or lefs, in every part of the body. And this fhews why the whole body is nearly of the fame temperature; whereas, if the caloric were evolved in the

F 2

lungs

lungs only, that part of the body would be much warmer than any other, which is not the cafe.'

Mr. C. fuggefts it as a matter not improbable, that both the carbonic acid gas and the water, inftead of being formed in the lungs, may come out of the blood, through the exhaling pores of that organ, ready formed, the blood having originally received it in that ftate from the chyle,' &c. To us, however, it appears much more probable, that thefe fubftances are formed in the lungs by new combinations. But hear the author's ingenious arguments in favour of his fuppofition.

P. 85. It is difficult to account for the formation of the carbonic acid gas, and of the watery vapour in the lungs; for if thofe fluids be really formed in that organ by the combination of the carbone, and of the hydrogen, with the oxygene of the infpired air; the whole, or nearly the whole, of the oxygen air would be fo expended, and little or none of it would remain to be imbibed by the blood. The caloric likewife would be employed in the formation of those fluids, inftead of being difperfed through the body. Is it not therefore more natural and more fatisfactory to fuppofe, that both the carbonic acid gas, and the water, are feparated from the blood in the lungs, but not formed in that organ? It is certain that carbonic acid gas is introduced into the ftomach by the aliments; and it is certain that the chyle conveys it to the blood, why then fhould we fuppofe that there is another formation of this gas in the lungs? As for the watery vapour, we may account for it in the fame manner; and indeed the exudation of water through the internal membranes of the human body, is fo generally practifed by nature for the purpose of keeping thofe membranes, &c. foft and pliant, that it would be irregular not to admit the fame exudation of water in the lungs alfo.'

The chapters containing directions for the application and adminiftration of aerial fluids in the cure of diforders, with the medical cafes and practical remarks, are, in many refpects, interefting to practitioners, and comprehend much ufeful, as well as neceffary, matter. From the cafes it may be fairly concluded, that, notwithtanding the mifapplication and abuse of these remedies in different inftances, they are, on the whole, capable of doing much good when administered with judgment.

On the nature of the blood, Mr. C. has done little more than bring the materials, that have been fupplied by others, into a narrower compass, and place fome of them in clearer points of view.

On the whole, the author's chief endeavour, in this work, feems to have been, the collecting, examining, and methodizing of the various facts that have prefented themfelves; and, by thus affording a more diftinct view of the fubject, to promote the ufe and prevent the abufe of aerial remedies. And, in this point of view, his publication will certainly be found valuable.

ART. XIII.

A. R.

An Inquiry into the Caufes and Effects of the Vario'a Vaccine, a Difeafe difcovered in fome of the Western Counties of England, particularly Gloucestershire; and known by the Name of the Cow Pox. By Edward Jenner, M. D. F. R. 9. &c. 4to. 75 pages, and coloured plates. Price 7s. 6d. Law. 1798.

THE

THE author of this inquiry obferves, that the cow pox has been long known to farmers in the weft of England: but that it's origin and effects have not been, till of late, properly afcertained. The disease appears on the nipples of cows, in the form of irregular puftules, which are, at firft, of a pale blue, or fomewhat livid colour, and furrounded by an extenfive border of inflammation. These puftules often terminate in phagedenic ulcers, which prove extremely troublesome. The animals become feverish; and the fecretion of milk is leffened. Domeftics employed in milking the cows are prefently affected about the joints, and at the extremities of the fingers, and fometimes on the wrifts, with fmall vefications, or puftules. Thefe enlarge, and fuppurate quickly: they appear of a bluish colour, and have always a circular form, their edges being more elevated than their centres *. Tumours arife in the axilla: after which a confiderable disorder of the conftitution takes place for one, two, three, or four days, and is fucceeded by ulcerations on the hands, very difficult to heal, and often phagedenic. Sores are likewife produced on the lips, noftrils, eyelids, &c., from carelessly rubbing thefe parts with the infected fingers.

Dr. J. is of opinion, that the cow pox is not generated by any previous difeafe of the cow, but that it originates from another animal in a diseased ftate. The fuppofed mode of it's communication will be most properly delivered in the author's own words:

In this dairy country a great number of cows are kept, and the office of milking is performed indifcriminately by men, and maid fervants. One of the former having been appointed to apply drefsings to the heels of a horfe affected with the greafe, and not paying due attention to cleanliness, incautiously bears his part in milking the cows with fome particles of the infectious matter adhering to his fingers. When this is the cafe, it commonly happens that a disease is communicated to the cows, and from the cows to the dairy maids, which spreads through the firm until moft of the cattle, and domeftics feel it's unpleafant confequences.'

The circumftance which principally demands attention, in regard to the cow pox. is, that any perfon, who has been once affected with it, will never afterwards take the fmall pox, either by expofure to variolous effluvia, or by inoculation. This point, as well as the truth of his idea, refpeting the origin of the difeafe, the author has endeavoured to establish by a variety of cafes and experiments.

It appears farther, that those who have had the fmall pox, either efcape the cow pox, or are difpofed to take it flightly: thus, by milking infected cows, they may get fores on the hand, without being fenfible of any general diforder. Dr. J. however, allows, that the cow pox does affect the fame individual repeatedly: but he obferves, that the fecond and third attacks are, in general, much more flight than the first.

Some other remarks or inferences, made by the author from his cafes and experiments, deferve to be noticed.

The pustules are well represented, in their differen Itages, y a feries of coloured plates, drawn by E. Pearce, and engraved by Skelton.

F 3

1. He