The fubjects of chemistry are next confidered in the fecond chapter. Thefe are diftributed (to use the author's own words) into eight different claffes, viz. heat, light, air, water, earths, falts, metals, combustibles, the mephitic gafes, and magnetic fluid. Here the author must have committed a mistake; he mentions eight claffes, and yet enumerates ten. "Of thefe fubftances(fays he) the three first, together with the firft of the ninth clafs, are elements; all the reft are compounds." Here again the reader will not be able to find out which of the gafes he alludes to, unless he looks forward twenty-four pages; but from whence he is to derive this forefight we are not able to conjecture. Befides these four genuine elements, he mentions twentynine fpurious or occult elements, viz. the base of fulphur; of phofphorus; of the muriatic acid; of the fluor acid; of the acid of borax; the organic bafe or vegetable principle; the base of gold, or earth of gold; of filver; of copper; of iron; of tin; of lead; of platina; of mercury; of zinc; of manganese; of nickell; of antimony; of bifmuth; of cobalt; of arfenic: of molybdæna; of barylithium; pure filiceous earth; pure calcareous earth; pure muriæcie earth; pure barytes: pure alumite; hydrophlogium, or the bafe of water and inflammable gas. The agency of heat, and its effects on different bodies, are firft confidered. This is explained and elucidated in a tolerably clear manner. We have next a fhort and well written differtation on specific heat, by M. Gadolin, profeffor of chemistry, at Abo, in Finland. To this we find fubjoined a table of the capacities of heat in different bodies. Light is the fubject of the fecond fection. The editor here confiders light as a fimple body, which, when united to heat, conftitutes fire; and light, when united to heat, and any fenfibly gravitating matter, conftitutes phlogiston. This theory was prefented to the public in the year 1781, under the title of An Effay on Fire. We fhall pass over the third fection on air, and the elaftic fluids in general, as containing nothing new or particularly ftriking. Water is the fubject of the fourth fection. In regard to its conftituent principles, the editor appears to coincide with M. Lavoifier, only he will have it, that the fire, or the light and heat, difengaged during the union of light, inflammable air and dephlogisticated air, is the phlogifton of the light inflammable air; for, fays he, "As to the inflammable gas, which M. Lavoisier feems to confider as a fimple fubftance, it is inconceivable how water, which is abfolutely incombustible, should have fo combuftible a substance as inflammable gas is, for one of its component parts." With the fame force of reafoning we might fay-it is inconceivable how vitriolated tartar, or kali, which has no acid property, fhould contain fo acid a fubftance as the vitriolic acid for one of its component parts. The fifth fection relates to the earths, in which a distant account is given of their leading and characteristic properties. In the fixth fection the falts are treated of: They are divided into fimple and compound. Simple falts are either acids or alkalies. The compound falts are acids and alkalies united; and are divided into double, triple, and quadruple. The double falts are subdivided into neutral, hyperoxea or fuperacidated and hypoxea or fubacidated. Each of these orders are further divided into faline, earthy, and metallic falts. The different faline bodies are arranged or claffed in a scheme or table, according to the different genera, and have new names affigned them. We apprehend that Dr. Hepfon will find very few admirers of the arrangement and divifion in this fection, and ftill fewer of the nomenclature, which is fo particularly harsh and polyfyllabic, that, we conceive, the English reader will hardly be able to articulate fuch fefquipedalia verba. In the feventh section are given definitions of metallic fubfrances in general, to which is fubjoined a lift of their different names. Combustibles are arranged and defcribed in the eighth section. The exclufion of the metals, and the admiffion of the electric fluid into the clafs of combuftibles, are among the peculiarities that distinguish this fection. According to our own definition of combuftion, and conformable to our ideas of the electric fluid, we are by no means inclined to agree with our author in the propriety of his claffification; he must advance fome more perfuafive arguments in its favour, than he has already done, before he will be able to win our affent. Section the ninth comprehends the mephitic gafes; and the tenth the magnetic fluid, which concludes this chapter. The third chapter gives us a tolerably good definition of faturation and chemical analysis and finthefis. The fourth chapter treats of chemical inftruments, which are divided into active and paffive. The active are; heat, light, air, folvents, precipitants, reagents. The paffive inftruments included the whole apparatus used in chemistry. This is diftributed into four claffes, viz. furnaces, veffels, inftruments, and lutes. The utility of what are denominated active inftruments, is very well pointed out; which is more than we can by any means fay of what comes under the title of paffive inftruments. The furnaces defcribed are in no refpect equal to those which are at prefent used in England, and the defcription even of thofe, Lad as they are, is very imperfect and obfcure. Ꮓ 3 Wa We fhall give the following extract as a specimen; which must fufficiently confirm the truth of what we affert, at least to fuch of our readers as are already acquainted with the prefent improved ftate of chemical furnaces in this country. We are obliged to quote his own words refpecting the fand furnace, as he refer- it in the fubfequent paffage, which we mean to point out. The fand furnace, which takes its name from the fand pot, the veffel chiefly used in it, is defigned for various operations, fuch as, digeftion, dilillation, evaporation, and fublimation. This furnace may be either portable or fixed, according to its fize. The form of it is generally quadrangular. If, inftead of a fandpot, which veffel we fhall defcribe a little farther on, a copper caldron is fet in this furnace, it may alfo ferve for a balneum maria. The reverberatory furnace, (he in the next place obferves), refembles that immediately preceding in its whole ftature, excepting that across it, juft over the fire-place, two ftrong iron bars must be fixed in the brick-work, for the purpofe of fupporting the retorts that are to be laid on it. It is ufed in the diftillation of mineral and acid fpirits, empyreumatic oils, volatile falts, phofphorus, and many other fubftances. Thefe veffels, which are either of ftone ware or glafs, are expofed to a naked fire, on which account they should be coated with a compofition of clay, &c. in order to prevent them from eafily burfting. For the purpose of encreafing the fire a tower may alfo be added to this furnace. This furnace may likewife be conftructed in fuch a manner that many retorts may be fet upon it at a time, and wrought with the fame fire.' The editor has indeed afterwards, in one of his notes, spoken of Dr. Price's portable furnace, but makes no fort of mention of Dr. Higgins's different furnaces, from which Dr. Price took the model of his. The glass apparatus is tolerably well defcribed; but is too ancient in general to deferve the attention of the English chemift. The earthen apparatus is diftinctly explained, and likewife the different purpofes, for which it is intended. The defcription alfo of the metallic apparatus, &c. is likewife pretty accurate. Some of the lutes are complex, and the mode of applying them rather tedious and troublesome. We have further to obferve, that feveral things are omitted which are of effential importance in furnishing an elaboratory for the complete convenience of an experimenter. In the fifth chapter the various operations of chemistry are explained, fuch as diftillation, fublimation, calcination, fufion, folution, infpiffation, precipitation, crystallization, and reduction.Diftillation is very well defcribed; yet we do not at all agree with the author in fome parts of his reafoning. Sublimation is very philofophically described. In the elucidation of the nature of calcina tion the author's reasoning and inferences, drawn from the facts which he adduces, indicate a very imperfect acquaintance with the doctrine and general principles of fineumatic chemistry. Solution, on the contrary, is illuftrated in a fufficiently perfpicuous and fcientific manner, fo much fo, that one would almost suspect that it was the compofition of a different author. We fhall now pafs from this to the fection following; which contains only a fynoptical view of the operations of chemistry, which are arranged and exhibited in a table annexed thereto. The fixth chapter, relative to elective attractions, contains nothing of particular importance. In the feventh chapter are laid down general rules to be obferved in chemical inquiries, which are certainly judicious and worthy of notice. This fubject clofes the first part of this volume. [To be continued. ] ART. VII. Senilia; or, An Old Man's Mifcellany. By the Rev. Mr. Skelton, aged Seventy-nine. Vol. VII. 8vo. 65. boards. Sleater, Dublin. 1786. ΤΗ HIS is a feventh volume of our reverend author, but no way connected with the former; it confifts entirely of extemporaneous anecdotes and obfervations which have occurred during a long life. It is difficult to form a digest, or even to give an opinion of fo mifcellaneous a production; we shall only fay, fome of the observations are new and ingenious, many more trite, but for the most part written with fpirit. We have felected the following as occuring in order, yet directed to different fubjects: 27. Many good Chriftians, and even fome eminent writers, affect to believe that our friendships and attachments, formed in this world, will be protracted into, and make a part of, our happiness in a better. How low, and contrary to the mind of Chrift, is this fond imagination! Do we ever confider the connexions we form with other children, ere any of us are two years old, of confequence enough to be carried up to the age of forty or fifty? How much more trifling are thofe we form here in an advanced age, to fuch as await us in heaven, where there can be but one, namely with God, and all that is good, and that fupported by infinite love, which can leave no room for lower and lefs ardent affections. It is true we fhall know one another, but only fo as to be witneffes for or against one another, in julification of the fentence pronounced at the laft day. Were the affections we feel here to be everlafting, they would be oftener an occafion of mifery than happiness, inafmuch as Z 4 poffibly poffibly we might perceive that an hundred of thofe we formerly loved are excluded, for one that is admitted into the place we are in. God is the centre of all the happy, of all that we fhall then be capable of loving; and, as to thofe that are fhut out, we fhall abhor them as enemies to God, and affociates of the devil This whimfical expectation is likewife contrary to the word of Chrift. In reafoning with the Sadducees he founded his argument on an abfolute denial of it in regard to man and wife, the closest and dearest of all our connexions in this life; and, a fortiori, on the like denial of all fubordinate attachments formed here. In the refurrection,' he tells us, we fhall be as the angels in heaven.'. The friendships of this world, howfaever pure and exalted, would be very unfit to be carried up fo far, and could but produce detachments from that tendency of heart and foul to God, and that facred love of all that are truly his, which are to fwallow up all the powers of our nature. Of all other friendships formed here below, that between man and wife, for certain reafons which I need not mention, are the leaft fit to be carried thither. 28. Cunning is nothing else but the fool's fubflitute for wisdom. A poor shift indeed! 29. People, quoth dame Fashion, may rail at death, if they will; but, upon my honour, mourning is a great advantage to poor gentlewomen. Here am I putting on thefe fables the fourth time; and after, with a little coaxing and mending, they may ferve me a fifth turn, when my dear Jack fhall leave me a widow. Jack is a very hard drinker, and drinks I think, but the more for my scolding; well, every body fays I look handfomer in black than in colours. My blacks may therefore be of more ufe to me yet, than barely faving me a little money. Tongue, do thy office; and may my teeth bite my hand if it attempt to hold thee.' This will be enough to fhew the general defign of the work. Mr. Skelton's name is well known by his former productions. ART. VIII. Philofophical Tranfactions of the London, Vol. LXXV. For the Year 1785. 8s. 6d. fewed. Davis. London, 1785. Royal Society of Art. XVI. ON the rotatory Motion of a Body of any Form whatever, revolving without Restraint about any Axis paffing through its Centre of Gravity. By Mr. John Landen, F. R. S. Mr. Landen, in the Philofophical Tranfactions for 1777, and in Mathematical Memoirs, has fhewn that any body, of certain dimenfions and uniform denfity, if made to revolve freely on any axis paffing through its centre of gravity, will continue to revolve about the fame axis. Should the axis not be permanent, the rotatory must be disturbed, and its poles continually varying; on which account it is doubtless a matter |