affumptions (which they are reduced to fuppofe for want of the neceffary data) must be extended into a very confiderable one in the course of the calculation, much of that time. is unprofitably expended in it, which might have allowed of real improvement from the lights of experience, autopsy, and experiment. But this by the way.

Our author illuftrates the neceffity of good maftication, in order to good digeftion, which is as neceffary again to a perfect chylification, as this is to a recruit of good blood, by ingeniously obferving, that birds, who are not furnished with teeth, have a first stomach or craw, in which their food receives fuch a softness and humidity, as is fome equivalent for maftication, before it is detruded into the second stomach or gizzard, from whofe remarkably strong muscles it is reduced to that mature comminution, neceffary to allow an expreffion of its nutritious juices.

Upon the article of preferving the teeth, having condemned immoderate drinking, the habit of fmoking, too fudden a fucceffion of hot and cold aliment, the cracking of hard bodies, and the like, he justly concludes, as follows:

The great prefervation of our teeth, in fhort, chiefly depends on our regimen of living: the conftitution and the teeth have fo equal a dependence on each other, that the deftruction of the latter proves the ruin of the former, almoft as certain, as that a bad blood can never supply the teeth with good nourishment.'

After afcribing the difeafes of the teeth to internal and external causes, he fuppofes the former to depend either on the noxious quality of the lymph, as in the fcurvy, king'sevil and pox, or on the fuperabundance of it, whence it may ftagnate between the alveoli, and the roots of the teeth, occafioning obftruction, inflammation, and fuch acute pain, as may be incurable without extraction of the tooth. But our author is not fo clear and intelligible where he affirms, p. 22. that too much fleep, too much watching, a too fedentary life, or a too laborious one, contribute not a little to the preservation, or the ruin of the teeth; fince this leaves us uncertain which of these exceffes contributes to preferve, and which to ruin them; when it seems a more rational conclufion, that all exceffes are prejudical to them, according to the axiom,---omne nimium malum.

Mr. Tolver confiders even the paflions as internal causes of the diseases of the teeth, as they affect the fecretions and the crafts of the blood; from whence indeed they may be

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referred to the pony, or pre difpofing caufes. But tho there is probably fome truth in this aetiology, it appears a little fine fpun; and it may be queried, whether thofe who call the tooth ach a love-pain, have done it from the fame Theory? Among internal difeafes he obferves the jaundice to be particularly prejudicial to the teeth.

He afcribes the difeafes of these bones, from external causes, to a tenacious, viscous fubftance, produced by grofs vapours from the ftomach and lungs; to defluxions, from taking cold; to the ufe of dentifric powders; to a neglect of cleaning them, and to the effects of mercury: we fuppofe he means, to be methodical, from the external application of it, fince we know of no dentifric into which it enters; and mercury taken internally, which even the unction in effect is, feems full as referable to the, internal caufes. But indeed it may be doubted, whether internal vapours, or even defluxions, can with ftrict propriety be ranged amongst external causes, tho' the cold occafioning the defluxion may; in which fenfe mercury, as being conveyed ab extra, may alfo. And where the external fubftance of these bones is vifibly attacked, the disease may be termed external, where the immediate caufe is not. We may obferve, en paffant, that this author feems to have confulted chiefly the French writers on this fubject; who, befides their attention to the general falutary purposes of found teeth, may be supposed to have confidered them more exactly than our own, with regard to ornament, or even as a part of drefs, which that nation are fuch extensive regu

lators of.

Having reduced the difeafes of the teeth, from above a hundred, enumerated by authors, to nineteen, and left us ftill enough of them, he mentions their fenfibility and agacement, which, in fact, is but a particular mode of fentibility. By their fenfibility, however he understands the toothach, and by the French term what he defines, an acute pain, (though it feems rather an uncouth, difagrecable fenfation) on their being fet on edge by certain founds, as the touching of ftuffs, flipping of a knife on china, filing of iron, &c. Whether the fimple touching of ftuffs will produce this effect generally, the contact of woollen ones with, or their compreffion between, the teeth, will certainly do it with most people; as the very fight, or even idea, of it will affect fome. But how this fenfation, this ag cement, is occafioned by found, our author is wholly filent; contenting himself with doubting, whether the general opinion of a

fcribing

fcribing it to an acid juice is well established, fince the chewing of forrel will immediately remove it. We are convinced, however, that spirit of vitriol, verjuice, or lemon-juice, in a fmall quantity, will produce it; tho' a moderate quantity of common vinegar fcarcely does. This may perhaps be obviously referred to the manifeft action produced by the commixture of the former acids, not only with the lixivial alcalies, but even with powder'd oifter-fhells, bones, and the like, which being added to vinegar, rather produce an infipidity of, than a visible luctation with, it. But if, with regard to the modus of founds occafioning the agacement, we fuppofe particular, uncouth, and grating ones, to affect the chorda tympani, and the minute nerves of the muscles of the malleus(which are both fpigs from one of the branches of the fifth pair) in an extraordinary manner, it will not feem very improbable. that an uncommon violent vibration of them may fenfibly affect thofe fmall nerves, which are detached to the teeth of both jaws from branches of the fame pair: thofe going to the mufcles of the malleus, that conftituting the chorda tympani, and those fent to the teeth of the lower mandible particularly, iffuing all from the third branch of the fifth pair; the teeth of the upper mandible being fupplied from the second branch. And fince the teeth may be' confidered as moft acutely fenfible, it is poffible the nervous fibrils may be propagated into their hard and intimate fubftance, beyond the reach of anatomy and microscopes, and effect fuch a thrilling motion, in them, as may be analogous to the tremors of the fibres in hard and fonorous bodies, and which motion is perhaps the immediate cause of this odd fenfation in the teeth, which feems pofterior to that of the ear, tho' fo very fuddenly fucceffive, as to pass for inftantaneous. Whether this folution of it be adequate, or not, feems indeed of little practical confequence: but having met with none before, we fubmit this, for its novelty at least, to our medical readers.

In his fection of the methods of cleaning the teeth, mr, Tolver condemns alike the alcalious dentifric powders, and the acid juices, applied for that purpofe; as they tend to abrade or corrode the enamel of the teeth, and subject the denuded bone to a caries. He condemns the ufe of brushes, and even of bits of linen; and advises to clean them with a piece of fpunge dipped in warm water, in which fome foap has been diffolved, which he greatly approves from its penetrating, deterging nature. He thinks the morning the eligible time for this work, after removing Y 3

the

the viscous fubftance from their furface with a quill; and proposes rincing the mouth after with a little Hungary water, fpirit of lavender, or the like, diluted with warm water. He much difapproves the practice of fcaling the teeth, fo much in vogue; and feems indeed to have intended his pamphlet as fome caution against the present fashion of paying foreign dentifts, as they have been called, fo extravagantly, for injuring, and even destroying, fuch necessary parts. On this head he obliges us with the following fact, which, it must be supposed, a gentleman of probity would not have affixed his name to, without a certain knowledge of.

A certain merchant in the city, though otherwife sufficiently covetous, bestowed a confiderable purfe upon one of our foreign operators; who had in good truth changed the colour of his teeth, from a black to a very beautiful white. But, behold the confequence! The merchant found himself under a neceffity of befpeaking a new fet; for they all actually fell out, one after the other. I faw him within three months after the operation, when he had only two remaining in his head. This, fays our author, is an inftance not without its precedent.'

We hope what appeared to us a material caution in phyfical reafoning, and a fhort hypothefis, which we intended for the fervice and entertainment of young medical readers, will be confidered as fome excufe for our prolixity on this fmall treatise.

ART. XXXVIII.

The two questions, previous to dr. Middleton's free enquiry impartially confidered, &c. Part. II. By dr. Sykes. 8vo. 2s. 6d. Knapton.

THE piece now before us is a defence of the two previous questions, in anfwer to the objections urged against them by dr. Dodwell in the preface to his final reply to mr. Toll's defence of the free enquiry. Our learned author has taken occafion to enter into a full examination of the evidence for the miracles of the primitive church, and endeavoured to make it appear, that no better evidence can be produced for the miracles, faid to be done in the fecond and third centuries, than may be produced for those of the fourth, or fifth, or fifteenth. It were to little purpose to detain our readers with a long account of what he says; fince, after what has been written upon the controverfy concerning

For the doctor's first part, fee Review, vol. II. p. 270.

concerning the miracles of the primitive church, it may be fairly prefumed they are fufficiently acquainted with the

merits of the cause.

The doctor concludes his performance, which is written in a very genteel manner, with the following, reflection. If any one thinks the evidence for miracles, fays he, during the fecond and third centuries ftrong, and fufficient enough, for his affent, let him believe them if he can: but let him not condemn another who thinks that he has rea⚫ fon to doubt or fufpect them For a man may be a fincere chriftian, and he may be able to prove the gospel miracles credible, and he may believe them too, notwithstanding he may not think that there is fufficient evidence for miracle fince the death of the apoftles.'

any one

ART. XXXIX. A fequel to the effay on fpirit: Being the refult of a fair and serious enquiry concerning a very important doctrine of the chriftian religion, as delivered in the facred Jcriptures. With fome obfervations relating to the Athanafian and Nicene creeds. Addreffed to his grace the lard archbishop of Canterbury. 8vo. I s. 6d. Noon.

I

N an advertisement prefixed to this fenfible, candid and modeft performance, we are told, that the greatest part of it was drawn up before the essay on Spirit appeared; and that all of it was finished, before that effay was feen by the writer; who, having penned it for his own fatisfaction, and that of a few friends, had no intention of making it public at that time, and would probably have fuppreffed it much longer, but that he had reafon to believe it might be of fome service towards clearing a very important fubject, at a juncture when he found it was brought under fresh enquiry.

Our author introduces it with acquainting his readers that, being defirous to fatisfy his mind, in the best manner he can, concerning a fundamental article of the chriftian religion, he chufes to go immediately to the fountain-head, the holy fcripture, as being the fureft guide he can make ufe of, in order to attain the fatisfaction defired. I think I plainly fee, fays he, that the fcripture is uniform in its declarations, and that it has pointed out a plain and easy way whereby men may come at truth.

The way is, to begin with the plainest and most obvious principles it lays down; to fix upon them as certain

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and