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grinder, may be perceived in a foetus of feven or eight months, and the offification begins in them about fix' months after birthi Soon after birth the fecond incifor, and the canine tooth on each each file, begin to be formed. About the fifth or fixth year the firit bicufpis, and about the feventh the second bicufpis, begin to ofify. Thefe bicufpides are destined to replace the temporary grinders. All thefe permanent teeth are formed in a diftinét fet of alveolf; 'so that it is not by the growing of one tooth under another, in the fame focket, that the uppermost tooth is gradually pushed out, as is commonly imagined; but the temporary teeth, and thofe which are to 'fucceed them, being placed in separate alveoli, the upper fockets gradually difappear, as the under ones increafe in fize, till at length the teeth they contain, having ne longer any fupport, confequently fall out.

But, befides these twenty teeth which fucceed the temporary ones, there are twelve others to he added, to make up the number thirty-two. Thefe twelve are three grinders on each fide in both jaws; and, in order to make room for this addition, we find the Jaws grow as the teeth grow, fo that they appear as completely filed with twenty teeth, as they are afterwards with thirtytwo. Hence, in children the face is flatter and rounder than in adults.

"The fir adolt grinder ufually paffes through the gum about the twelfth year; the fecond, which begins to be formed in the fixth or feventh year, cuts the gum about the feventeeeh or eighteenth; and the third, or dens fapientiæ, which begins to be formed about the twelfth year, paffes through the gum between the age of twenty and thirt. The dentes fapientiæ have, in fome inftances, been cut at the age of forty, fifty, fixty, and even eighty years; and it fometimes happens that they do not appear at all.

"Sometimes likewife it happens, that a third set of teeth appear about the age of fixty or feventy. I have never feen any inftance of this kind myself, but there is no doubt that such cases do now and then occur. Diemerbroeck * tells us, that he himself, at the age of fifty-fix, had a fresh canine tooth in the place of one he had loft feveral years before; M. du Fay faw two incifores and two canini cut the gum in a man aged eighty four. Mr. Huntert has feen two fore-teeth fhoot up in the lower jaw of a very old perfon

fame kand an account was lately published, of a man who

had a

fet at the age of lixty §. Other inftances of the

are to be met with in authors. The circumftance is curious, and, from the time of life at which it takes place, and the return of the catamenia, which forietimes happens in women at the fame age, it has been very ingenioufly fuppofed that there is fome effort in nature to renew the body at that period,

Anat. Corp. Human.

+ Mem. de l'Acad. des Sciences, 1938. Nat. Hift. of the Teeth. S Med. Comm. of Edinb. vol. iii. Hunter's Nat. Hift. of the Teeth.

The

"The teeth are fubject to a variety of accidents. Sometimes the gums become fo affected as to occafion them to fall out, and the teeth themselves are frequently rendered carious by caufes which have not hitherto been fatisfactorily explained. The difeafe ufually begins on that fide of the tooth which is not expofed to preffure, and gradually advances, till an opening is made into the cavity: as foon as the cavity is expofed, the tooth becomes liable to confiderable pain, from the air coming into contact with the nerve.

"Befides thefe accidental means by which the teeth are occa fionally affected, old age feldom fails to bring with it fore and natural caufes for their removal. The alveoli fill up, and the teeth confequently fall out. The gums then no longer meet in the fore part of the mouth, the chin projects forwards, and the face being rendered much fhorter, the whole phyfiognomy appears confiderably altered.

N

Having thus described the formation, ftructure, growth, and decay of the teeth, it remains for us to fpeak of their uses; the chief of which we know to be in maftication. And here we cannot help obferving the great variety in the ftructure of the human teeth, which fits us for fuch a variety of food, and which, when compared with the teeth given to other animals, may, in fome measure, enable us to explain the nature of the aliment for which man is intended by nature. Thus, in ruminant animals we find incitores only in the lower jaw, for cutting the grafs, and molares for grinding it; in graminivorous animals, we fee molares alone; and in carnivorous animals, canine teeth, for catching at their prey, and incifores and molares, for cutting and dividing it. But, as man is not defigned to catch and kill his prey with his teeth, we obferve that our canini are fhaped differently from the fangs of beats of prey, in whom we find them either longer than the rest of the teeth, or curved. The incifores likewife are fharper in thofe animals than in man. Nor are the molares in the human fubject fimilar to the molares of carnivorous animals; they are flatter in man than in these animals; and, in the latter, we likewife find them fharper at the edges, more calculated to cut and tear the food, and, by their greater ftrength, capable of breaking the bones of animals. From thefe circumftances, therefore, we may confider man as partaking of the nature of thefe different claffes; as approaching more to the carninivorous than to the herbivorous tribe of animals; but upon the whole, formed for a mixed aliment, and fitted equally to live upon flesh and upon vegetables. Thofe philofophes, therefore, who would confine man wholly to a vegetable food, do not seem to have studied nature. As the molares are the last teeth that are formed, fo they are ufually the fift that fall out; this would feem to prove, that we require the fame kind of aliment in old age as in infancy.

"Befides the ufe of the teeth in maftication, they likewife ferve a fecondary purpose, by affifting in the articulation of the voice,"

To

To the above extract, from the performance, we shall only add our hearty wishes that the author may have health and leisure to put a finishing hand to a work for which he feems fo ably qualified, and which cannot fail to gain him a diftinguished rank among the medical writers of the prefent century.

A Sermon on the Duty of Compaffion towards poor Brethren, preached before the Scots Corporation in London, at their Anniverfary Meeting, St. Andrew's Day, 1778. By Henry Hunter, D. D. Chaplain to the Corporation. 8vo. 1s. Donald

fon.

The Scots corporation was formed foon after the reftoration of Charles 2d. Its defign, fays Dr. Hunter, is to promote one of the best of purposes, the relief of the aged, the poor, and the miferable.'

*

To excite the attention of his auditors to compaffion, the Doctor delivered this difcourfe. His text is taken from Deut. 15, 7, 11. In which words we clearly difcern the generofity and benevolence difplayed in the laws given to the Ifraelites of old; amiable in themfelves, and the means of joy and relief to the diftreffed. But we, indeed, who are guided by the glorious light of the everlafting Gofpel, are fubject to greater obligations to break forth into acts of charity. A performance of this duty with fimplicity' will greatly contribute to exalt us in glory. Our bleffed Saviour was a father to the fatherless. He is the moft excellent pattern to be imitated. It must be highly pleafing to the Deity, who is father of all to fee us extend our pity and compaffion to our brethren, who are in the bitterness of mifery. This too is the end of the commandment. And by this the receiver is enabled to enjoy the comforts and conveniences of this life, and the giver purchases for himself, the bleffed happiness that attends another.

6

This fubject is frequently written upon, fo that great_novelty of fentiment cannot be expected. However, the Doctor hath here prefented us with a fenfible and pertinent difcourfe. His language is nervous and manly, and in fome places we are affected with the true pathos.

After mentioning the inequality of mankind, the Doctor obferves

that,

"The business of the world, in every department must of neceffity be carried on by the affiduity and frength of the many

and

and every man needs a motive to engage him to exert bis ftrength and industry; and no motive is fo powerful and perfuafive as neceffity, and there is no neceffity fo cogent, as that of having daily bread. This, therefore, likewife difcovers a reafon, why the poor fhall never ceafe out of the land. Poverty is the mighty fpring which puts and keeps the great machine in motion, It is poverty which fets invention to work, which whets the genius, which braces the nerves, which fupports the fpirits. It is poverty that plunges into the mine, and penetrates into the polar regions; that yokes the patient feed, and puts the plastic loom in motion; that spreads the fail, rears the column, and embattles the host. It is poverty which, of course, gives ftrength and fecurity to Itates, aud majefty to kings; which creates wealth and diffufes happiness. It is the labour and induftry of the multitude, excited by poverty, which permits the philofopher to pursue, at leifure, his fpeculations, and the fatefman to form and profecute his plans; which provides inftruments to learning, embellishments to beauty,

and comfort to human life."

The following remarks are too juft to be paffed by unnoticed

It furely deferves notice, that fome of thofe things which remove men farthest from one another, and go the greatest length in destroying the idea of brother, are things entirely out of our power, independent of our will, and confequently undeferving either of praife or of blame. They ought therefore neither to excite pride, nor occafion fhame, fuch in particular is the circumfiance of birth, and its correfponding advantages or inconveniencies. High birth is then a real benefit, when it ferves as au incentive to noble actions; and obfcure extraction is honourable diftinction, when the man compenfates the meannefs of his origin, by the luftre of his virtues."

To this judicious difcourfe is fubjoined a short account of the inftitution, progrefs, and, prefent ftate of the Scottish corporation in London.

4

0.

The Comforts of Matrimony; or, Love's Last Shift: confifting of Matrimonial Dialogues, between Perfons, of all Ranks and Degrees, from the Peer to the Peafant; defcribing the Pains and the Plaafures confequent on Matrimony, and including a thousand Incidents most interesting and entertaining to every Married Perfon: comprising many Picces well worthy the No tice of the Unmarried of both Sexes. By Ned Ward, Junior. 12mo. Fielding and Walker.

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The most execrably dull doggrel we ever remember to have been peftered with, even in thefe-times of pactical famine.

FOREIGN LITERATURE.

FRANCE.

Hiftoire de l'Academie Royale des Sciences, &c.-The Hiftory.

of the Royal Academy of Sciences Records of the faid Academy, 4to.

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extracted from the

Paris.

Each volume of the Academy of Sciences is divided, as it is well known, into two parts. In the firft, the fecretary, under the head Hiftoire, gives extracts of the various effays and memorials read in the academy; an account of such facts ör obfervations that could not alone furnifh fufficient matter for effays, and concludes with the panegyric of thofe academicians who died within the year. The fecond part contains the effays or memoirs, fach as they have been read by the writers themselves at the meetings of the academicians.

For above five years that the Marquis de Condorcet has acted as fecretary, that part called Hiftoire has been treated in a manner peculiar to that celebrated writer. No commonplace differtations on the principles of thofe fciences which his readers are fuppofed to be acquainted with, can (as it is the care in most of thofe academical productions) difguft the reader, who, on the contrary, is prefented with found and novel reflections, not delivered in a magifterial and authoritative tone, but with that modefty and diffidence feldom to be met with in a man, who, befides being one of the greatest geometricians of the age, is alfo one of the moft chafte writers his country can boast of, and by the great abilities which he difplays on every fubject that comes within his province, fhews that he underftands equally well all the other parts that are the objects of enquiry. We are happy in this opportu nity of doing justice to a man to whom we are proud to lie under repeated obligations, and have the pleasure in doing fo, to be swayed ftill more by truth than inclination.

The volume we fpeak of contains, befide the Hiftoire, thirty-fix memoirs or effays on different fubjects; we fhall juft give a fhort account of fuch as we think moft worthy the attention of our readers.

Mr. Portal treats of the dreadful effects of the mephitic vapour. This effay was written in confequence of the death VOL. XI.

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