productum; that is, whether it previously exifts in the fubftances from which it is obtained, on the addition of acid liquors; or whether it is only an extemporaneous modification of these acids. He determines in favour of the latter opinion; but founds his determination on fuch grounds, as fhew him to be very little converfant, or at least very ill informed, with respect to the present state of this particular branch of knowledge.

To go even fo far back as Dr. Black's difcoveries, with refpect to the fixed air contained in lime-ftone ;-the Author obferves, that Dr. Black's hypothefis on this fubject was attacked, and that of Meyer was defended, by M. Crantz: and he expreffes his furprife, that none of the patrons of fixed air, have hitherto (to his knowledge) attempted to defend Dr. Black's theory, as far as they had it in their power.-Paffing over Dr. Black's powerful German fecond, M. Jacquin, who, in 1769, verified his experiments, and confirmed his theory by new ones; we need only to name M. Lavoifier, who, not very long afterward, fully established the credit both of the experiments and the theory, with a meafure and a balance in his hand. To these two philofophers alone we may safely refer the learned Author, for an answer to the various objections which he here propofes against this new theory of fixed air.'-We fhall only take notice of two of them.

When artificial nitre is made, by adding spirit of nitre to a fixed alcaline falt; the fixed air fuppofed to refide in the latter, is faid to be all expelled by the acid but if this were really the cafe, how happens it, fays the Author, that when the nitrous acid has been expelled from the alcali, in the fubsequent deflagration of the nitre with charcoal; and fresh fpirit of nitre is then added to the alcali deferted by it; as great an effervescence, and as large a quantity of fixed air prefents itself as at first ? Whence does this fresh stock of fixed air proceed?

It proceeds, we will inform the Author, from the particular inflammable fubftance employed to expel the nitrous acid; whofe place one of its principles immediately occupies at the very inftant of the deflagration. This, however, only happens when the inflammable matter employed in the process contains fixed air as is the cafe when charcoal is ufed. In the deflagration, the alcali receives its fixed air, or mephitic acid from the charcoal; in the very fame manner as it receives the vitriolic acid, when fulphur is employed in the deflagration. The Author must be too good a chemift not to know, that when filings of iron, zinc, &c. which contain no fixed air, are ufed in this procefs; the alcali left after the deflagration will not exhibit any appearance of fixed air, on the addition of spirit of nitre. This matter is fully explained towards the end of Dr. Priestley's Experiments and Obfervations, &c. Vol. III. p. 386.

After

After denying the exiftence of fixed air in lime-ftone, the Author endeavours to reduce the patrons of fixed air' to a dilemma, by the following reafoning. It is alleged by them, that lime owes its folubility in water, to the expulfion of its fixed air, by calcination: but magnefia, treated in the fame manner, is infoluble in water. He wishes to be informed, how effects thus contrary to each other, can be produced by one and the fame caufe. But furely the inference implied in this question is highly illogical. Can any thing be more natural, than that one and the fame fubftance may, by its prefence, or abfence, produce or occafion different effects in different bodies; or even in the very fame body, when the circumftances only are different? The Author next undertakes to prove, beyond any poffibility of doubt,' that all the earth of the prefent terraqueous globe was derived from water, as well as that which conftitutes the basis of vegetables and of animal bodies; and for this end, he endeavours to ascertain not only the poffible, but the actual tranfmutation of water into earth, in various inftances. He not only relates the many well known experiments, in which this tranfmutation appears to have been actually effected; but offers likewife various other obfervations tending to prove the poffibility of this converfion; which, however, are not of fuch a nature as to fatisfy even the leaft fcrupulous philofopher. It is far from our intention to treat a writer of fuch acknowledged merit as our Author with disrespect; but we must obferve that, in numerous inftances, which occur in this work, he is not very nice in his proofs; but employs any one that feems to serve the prefent purpose, indifcriminately;-whether ftrong or weak, and whether drawn from philosophy or fcripture: for to this laft the Author chufes likewife to appeal, even on philofophical queftions.

According to the Author, water is converted into earth, in the various processes of vegetation, animalisation, agitation, trituration in glass mortars*, putrefaction, coagulation, by means of the fparry acid difcovered by M. Scheele, and diftillation. With refpect to the refults attending this last process, our philofophical readers may confult the particular account we gave of M.

The Author affirms that by a long continued trituration of dif tilled water, without intermiffion, in a glafs mortar, he first produced veficles; that afterwards the water became less fluid, and appeared, as it were, coagulated; and that at last it was changed into a light white earth, adhering to the bottom and fides of the mortar. From only one drachm of water he declares that he obtained about one fcrupule of this white earth; which he affirms to have found, on examination, to be of a different nature from that which can be obtained from glass.

Lavoifier's

Lavoifier's experiments; [See Monthly Review, vol. L. Ap pendix, June, 1774. P. 544.] or Dr. Priestley's account of his trials made on water fubjected to a very strong and long continued heat, in tubes hermetically fealed; and which are contained in his late volume of Experiments and Obfervations, &c.

M. Lavsifier afcribes the earth which he procured by the diftillation, or rather cohobation, of the pureft diftilled water, to the abrasion of the particles of the glafs veffel containing it: as he found that the pelican which he employed had loft about as much of its weight, as was equal to that of the earth procured. The Author controverts this conclufion. He first questions the accuracy of the balance employed in this experiment. He does not think that M. Lavoisier ufed a fufficient degree of beat: [This objection, however, does not militate against the trials made by Dr. Priefley; who is inclined to fufpect that his procefies were not continued a fufficient length of time] but his principal objection to M. Lavoifier's conclufion is, that the lofs of weight obferved in the pelican, at the end of the experiment, might, with equal probability, be ascribed to the action of the fire on its external furface, as to that of the water on its inner furface properly obferving, however, that a chemical examination of the earth procured in the procefs, and a comparison of it with the fubtle powder of glafs, would beft fettle this point.

Having fhewn that both air and earth owe their origin to water, he confiders all natural bodies as confifting only of three principles; the inflammable, the faline, and water: and then refolving the faline principle into the aqueous and the inflammable, he concludes, that the principles of all natural bodies are neither more or less than two-earth- which is undoubtedly the principle fo called by Mofes,' [Gen. i. ver. 1.] and the matter of light, pure fire, celeftial fire, and which is denominated cælum by Mofes. The Author endeavours to fhew, how the various bodies in nature may be formed out of these two principles, in confequence of their different modifications, or the varieties introduced by figure, greater or lefs cohefion, &c.: but he labours ftill more ftrenuously to fhew, that his fyftem has the countenance of Mofes, in his hiftory of the creation; where he fuppofes him not to have given a partial hiftory of the creation of this earth, but of the whole vifible univerfe. The pious Author accordingly expreffes the utmost anxiety, left his philofophical and chemical principles, or his deductions from them, fhould be found contrary to thofe of the facred historian, and- Maximum phyficum, Mofen;'-who, we acknowledge, was undoubtedly killed in all the learning of the Egyptians-but how far that learning extended, with refpect to the philofophical part of the prefent inquiry, we can

not,

not, at this distance of time, determine. With fomewhat lefs impropriety, he endeavours to establish his fyftem concerning the formation of mountains, the deluge, &c. on the history of thofe events, as recorded by the facred writer.

In the preceding analyfis, we have confined ourselves to matters of a general nature; as we cannot, within any reasonable compafs, give even a fhort sketch only of the particulars of the Author's fyftem of the formation of the earth, and its fubfequent changes: as these matters are fo very complicated, and fo intimately connected with the Author's particular principles relative to the elements of bodies. For thefe the inquifitive reader muft fudy the work itfelf; from which we fhall only felect one particular object of the Author's investigation; merely as being more eafily detached from the reft.

This fubject relates to the exuvia of foreign animals, found in those parts of the earth where fuch animals do not, or cannot poffibly, now live. On this point, the Author maintains an opinion, not indeed with refpect to all the circumftances attending the phenomenon, fimilar to that of a late ingenious inquirer on this subject +:-viz. that they were indigenous, or lived in the very fame places, nearly, where they are now found; that thefe places had originally a different temperature, or state of atmosphere from the prefent; for that the air was then, in every part of the globe, equally temperate, and propitious to animal life.

To the changes in the earth's furface, or rather in the temperature of the air, effected by the univerfal deluge, the Author afcribes likewife the great change produced, with refpect to the age of man, immediately after that event. Some have afcribed the longevity of the Antediluvians to their temperate diet, and fober manner of living. The Author is far from adopting this idea, or even from being willing to allow that long life is to be obtained by temperance. The holy fcriptures,' fays he, intimate pretty plainly, that the Antediluvians were very far from living by rule ;-[ Nil minus quam diatetice vixerunt'] and that they were rather addicted, in the highest degree, to a life of pleasure and lafcivioufnefs. We are taught by daily experience, that the most regular regimen of diet contributes very little to long life.'

+ See Mr. Whitehurst's Inquiry, &c. or Monthly Review, vol. lx. January 1779, pag. 37.

B..y.

ART.

ART. XIV.

Brevis Introductio in Hiftoriam Literariam Mineralogicam, &c. A Short Introduction to the Hiftory of the Writers on Mineralogy: with an Effay on the propereft Method of forming a Mineralogical Syliem, together with a Supplement. By John Gotfch Wallerius, Profeffor of Chemistry, &c. 8vo. 6 s. fewed. Upfal, &c. 1779. Imported by T. Lowndes.

T

HE greater part of this useful publication was compiled, and published about ten years ago, by the Author of the preceding performance, under the title of Lucubrationum Academicarum Specimen primum. He has changed the title of the work, because he thought proper to digeft the materials intended for the promised continuation of it, into the form in which they appear in the performance, which is the subject of the preceding article.

The work itfelf is what the French would call a Catalogue Raifannée, of the various fyftems of mineralogy, from the time of Ariftotle down to the prefent; digefted in chronological order. In this compilation, the Author not only gives the titles of the various publications refpecting this fcience; but likewife a regular abftract of the different claffifications of mineral fubftances, invented or adopted by each writer respectively; together with his own occafional obfervations on the particular method, or system, of each of them. His great reputation, as a fyftematical writer in this branch of knowledge, renders it unneceffary for us to enlarge on the utility of this mineralogical Compendium to those who are engaged in the ftudy of foffils. To thofe who are more converfant in that science, it must be agreeable to fee here, as it were at one view, the gradual efforts made by human ingenuity, to clear up the immense chaos which the earth contains within its bofom; by difcriminating between the numerous fubjects of the mineral kingdom, and reducing them into order.-In giving a few fhort fpecimens of this performance, we fhall confine ourselves to the mineralogical writers of our own times.

"S58. JOH. HILL, Anglus. A General Natural History of Fofils. London. 1748." After giving, as a specimen of this work, the Author's claffification of earths and stones; he obferves, that his method is that of Scheufchzer and Woodward, fomewhat amended; and then characterises it as MIRIFICIS nominibus potius ONUSTAM quam ornatam.'

68. For fok til Mineralogie, &c. An Effay towards a Syftem of Mineralogy; by the Noble Axel Frederic Cronstedt, Stockholm. 1758 *.

This excellent work has been tranflated into English, and was published by E. Mendes Da Coits, in 1770. See Monthly Review, vol. xlii. April 1775.

After