ver, copper, iron, tin, lead; and deprived the five former of their ductility. On the combination of metallic oxids with the aftringent and colouring parts of vegetables; fhewing, that iron is diffolved by aftringent vegetables, but not by the colouring fubftances, which have no aftringency, as madder, brazil wood, &c. but that calces of iron, as alfo of copper, tin, and manganefe, are diffolved by thefe laft, producing fixity, and fhades, which may be advantageous in dying.

M. DE FOURCROY on azotic gas as a principle of animal fubftances: he finds this gas to abound in all animal matters, proportionately to the quantity of volatile alkali which they afford; that it is extricated by nitrous acid, in the temperature of 65° Fahr. and fpontaneously in the early ftage of putrefaction, whence the deleterious effects of the vapour iffuing in that ftage. Of azotic gas contained in the air-bladders of carp; and two new ways of obtaining it when thofe bladders are not to be procured he finds that manganese contains azote, which is extricated in the fame procefs with the vital air; that before the retort is red hot, the azotic gas alone is difengaged, but that, after this period, the vital air paffes nearly pure. On a remarkable alteration of the blood, occafioned by difcafe: drops of blood from the nofe, brownish while flowing, gave to linen a fine blue colour, which, in fome weeks, paffed to a dirty green, and, at length, to a yellow the author fufpects the colouring matter was analogous to Pruffian blue: perhaps it may rather be confidered as an inftance of oxygenation, agreeably to M. Chaptal's theory.-On litharged wines, and fome new methods of discovering the prefence of lead. We doubt that the teft liquor here recommended is rather too troublesome for common ufe: it is a folution of hepatic air in diftilled water, and must be prepared at the very inftant when it is to be employed.

M. DE MORVEAU on the dilatability of air and gafes by heat t various experiments on this fubject, with a tabular statement of them.

M. HASSENFRATZ on hydrogenous gas: this gas, by ftanding over water for three or four months, has been said to be changed into respirable air, but was found by this gentleman to fuffer no alteration in twelve months.

Befide thefe and fome other papers by the annalifts themselves, there are various extracts from Crell's Journal, from the Acta naturæ curioforum, and from other foreign publications of the time, relating chiefly to the analyfes of different mineral fubftances; among which the most remarkable are, thofe of the chryfoprafus and adamantine fpar, both by Klaproth: the former is found to be a quartz, coloured green by calx of nickel; the

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Jatter confifts of two parts of alum earth, and one of an earth unknown, fo intimately united, as to refift décompofition with unexampled obftinacy. This fpar, called adamantine, from its hardness, which is fuch as to fcratch cryftal, and to be applied for the cutting and polishing of fome gems, has been brought from the E. Indies under the name of corindum; and some specimens of it are here faid to have been found alfo in France.

We have been more particular in our account of this first volume, than its own magnitude may feem to require, or than we probably fhall be in reviewing those which may follow; and the reafon will readily occur. It is not yet too late for making alterations in the plan, by which the work might be rendered invaluable: materials may be collected with eafe, in fufficient plenty, and of excellent quality, requiring only to be compendiously and perfpicuously displayed; though it is obvious that, for this purpose, other abilities, than those of a mere tranflator, will be neceflary.

ART. XIII. On Electricity; with occasional Observations on Magnetifm. Pointing out the Inconfiftency and Fallacy of the Doctrine of Pofitive and Negative Electricity and investigating and explaining the true Principles, Compofition, and Properties of Electric Atmospheres. By E. Peart, M. D. &c. 8vo. pp. 92. 25. fewed. Miller. 1791.

DR. PEART urges fome plaufible objections against the com

mon doctrine of positive and negative electricity; and shews, from many circumstances of attraction and repulfion, that the bodies fuppofed to be in a negative ftate, or totally deprived of the electric fluid, have, apparently, as real an electric atmo fphere as thofe on which the fluid is fuppofed to be accu-, mulated. His own hypothefis is, that two fluids are concerned, which he calls, for diftinction's fake only, æther and phlogifton; that thefe Auids are every where prefent, naturally combined together, and ftrongly attractive of each other; that they are imperceptible to us while combined and quiescent, but inftantly manifeft their activity on being separated; that the feparating power, which excites one, gives a fimilar ex-` citation to the other alfo; that the two fluids arrange themfelves into atmospheres round the two bodies, or round two oppofite parts of one body, concerned in the feparation; and that each of these atmospheres confifts of two diftin&t airs, an internal of æther, and an external of phlogifton, or, contrariwise, an internal of phlogifton and an external of æther. A more particular explication of the author's hypothefis refpecting the arrangements of thefe fluids into atmospheres, and the laws

of

of their action, may be feen in his treatife on the Elementary Principles of Nature; and from the fpecimen which we have already given of it, (in the fecond volume of our New Series, p. 97.) we imagine that most of our readers have concluded, that there is more ingenuity in it than folidity. In the prefent publication, the Doctor confines himself chiefly to the folution of the electrical phenomena, and of magnetic attraction and repulfion, which he finds to proceed from the fame two fluids in a different ftate of excitation. At the conclufion, he extends his view, and contemplates the fame two fluids, either exifting feparately in different ftates of excitement, or coming together. in different ftates of activity, as having by him been proved to be the fole agents in all the operations of Nature:

In fhort, (he fays,) æther and phlogiston are the two active principles which produce the phenomena of magnetifm, electricity, gravitation, chemical affinities, light, fire, and all thofe active variations of Nature, which we contemplate with wonder, and gaze at with admiration! For proofs of what I now affert, I refer those who have inclination to know them, and candour enough to give them their due weight, to the full explanation I have given of them, in the Elementary Principles before mentioned.'

ART. XIV. Defcription of a Portable Cheft of Chemistry; or, Complete Collection of Chemical Tefts, for the Use of Chemists, Phyficians, Mineralogifts, Metallurgifts, Scientific Artists, Manufacturers, Farmers, and the Cultivators of Natural Philofophy. Invented by J. F. A. Gottling, Profeffor of Chemistry at Jena in Saxony. Tranflated from the original German. 12mo. pp. 194. 38. fewed. Kearfley. 1791.

THE portable cheft here offered to the public contains a

complete fet, very commodiously difpofed, of the different acids, alkalies, earthy and metallic folutions, vegetable colours, and the other tefts, or re-agents, neceffary in chemical analyfations; together with a blow-pipe, glafs mortar, fcales, &c. M. Gottling has taken great pains to afcertain the purity, and the effects, of the several preparations; and he has described the manner of ufing them, and of detecting the prefence of particular fubftances in any given compound, with so much clearness and precifion, that a man of common understanding, with little or no previous knowlege in chemistry, will be enabled by them to examine the nature and contents of fuch bodies as are commonly required to be fubmitted to chemical inveftigation. As it is our earnest wish that refearches of this kind may be rendered more familiar to manufacturers and workmen, as well as more convenient to others, we recommend this publication to all the defcriptions of men enumerated in the title-page.

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The preface informs us, that all the tefts are prepared by M. Hunneman, a friend of the author, and pupil of the two great luminaries of chemical fcience, Meffrs. Klaproth and Hermbftaedt, of Berlin;' and that the chefts are fold, completely fitted up, at C. and G. Kearfley's, No. 46, Fleetftreet; where any article, that may be expended, will be replaced. A little farther information on this subject would not have been amifs: without queftioning, in the leaft, either the skill or the care of M, Hunneman, we fhould like to know, whether he fends the preparations, in quantities, from the continent, or has an elaboratory in London; and in chemical preparations of fuch delicacy, we cannot much approve of apparent refponfibility being only in bookfellers. Happily, however, the experiments directed in the book itfelf, for examining the several tests, will generally difcover any material impurity or imperfection in them, wherefoever they may be procured.

The author first announced this undertaking in Sept. 1788, and is now employed on a continuation of it; which is to contain the analyfes made in the dry way, or by fire, not only of mineral fubftances, but of the vegetable and animal, having regard alfo to the feparation of the artificial claftic fluids; so that the whole may be confidered as a complete chemical elaboratory in miniature. Undoubtedly, (as he obferves,) a great number of experiments are yet neceffary to be made, in order to apply the apparatus, in the completeft and most commodious manner, to every cafe that may occur:' but he does not seem to have any doubt of being able to overcome all difficulties; and the ingenuity and perfeverance, fo confpicuous in the present performance, promise fair for fuccefs in the more arduous one which remains to be accomplished.

ART. XV. Baron Inigo Born's New Process of Amalgamation of Gold and Silver Ores, and other Metallic Mixtures, as, by his late Imperial Majefty's Commands, introduced in Hungary and Bohemia, From the Baron's Account in German. Translated into English by R. E. Rafpe With twenty-two Copper-plates, To which are added, A Supplement, or a Comparative View of the former Method of Melting and Refining; and an Address to the Subfcribers, giving an Account of its latest Improvements, and of the Quicksilver Trade. 410. pp. 290. 21. 2s. Boards.. Nichols, &c. 1791.

IT

T has been the general opinion of chemifts and metallurgifts, that filver, and even gold, are not always native nor metalhe in their ores, nor yet merely covered and difguifed by foreign admixtures, but often truly mineralized, like the base

metals;

metals; that is, in a calciform or unmetallic ftate, combined with fulphur or the other mineralizing materials; and as quickfilver does not act on any metal in this ftate, it has confequently been thought impoffible to extract the gold or filver from fuch ores by amalgamation. Baron Born contends, on the other hand, that the two precious metals never exist in this calciform or mineralized state; that they are never any more than difguifed by the mere appofition of other matters; that they may be divested of their disguise, whatever it be, by fimple and eafy operations, particularly by comminution and calcination; and may then be extracted by quickfilver, more completely, and at lefs expence, than by any other known means.

With regard to the author's main object, it is not of much importance in what state the gold or filver exifts in the ore; for he feems to admit, that metals, naturally calciform, may be rendered metallic by the preparatory calcination. Indeed, his ideas on this part of the fubject are not always very determinate nor confiftent; in one place he fays, that by this operation the bafe metals fhould be reduced from their calciform state into that of metal,' (p. 73.); in another, that the bafer metals, or femi-metals, from a metallic ftate are reduced into that of calx,' (p. 87.) Whatever may be the effect of the calcination in this respect, its utility for rendering the gold and filver amalgamable is very fatisfactorily established and explained.

The ores in queftion generally contain fulphurated iron and copper; and those which contain no fulphur, require fome fulphureous mineral to be added. In calcination, the fulphur is decomposed; its acid unites with the iron and copper by which the precious metals were enveloped; and the vitriols, hence refulting, being foluble in water, (which is a neceffary intermedium in the amalgamation,) the particles of gold and filver remain clean, and in a proper state for uniting with the quickfilver. For more effectually fecuring this great point, a quantity of common falt is mixed with the ore, previously to the calcination from the known laws of chemical affinity, the vitriolic acid quits the metals, to unite with the alkaline bafis of the fea falt; and the marine acid, thus difengaged, is of much more extensive activity than the vitriolic, diffolving nearly all the metallic substances that exist in thefe ores, (the gold and filver themselves excepted,) and forming alfo, with the foluble earths, faline compounds, either fpontaneously deliquescent, or of eafy folution in water.

On thefe general principles, the Baron finds amalgamation to be fuitable for every fpecies of mineral containing gold or filver, by only varying the proportion of common falt, and fome other circumstances, according to the nature of the mine

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