most important art. After he had at great expence made many private experiments, and was convinced of the utility of his method, he laid before the Emperor an account of his difcovery; who gave orders that a decifive experiment on a large quantity of ore should be made at Schemnitz in Hungary. To fee this, he invited many of the most celebrated chymifts and metallurgifts of Europe; and Ferber, Elhujer, Charpentier, Trebra, Poda, and many more were prefent, and approved of his invention. On this general approbation, he publifhed, by order of the Emperor, his Treatife on the Process of Amalgamation, with a great many engravings of the requifite inftruments and machinery. To fuppofe that his fuccefs, whilft it brought him fame and emolument, did not draw upon him the envy and ill-will of many of his brother metallurgifts and affociates in office, would how a great ignorance of what is daily paffing in common life. Envy has its fhare even in maintaining order in fociety: it is this which tends to keep the great from rifing higher, whilft a contrary paffion lifts up the little, or prevents them from falling ftill lower. Though great cabals were raifed against him, and against the introduction of his method, yet the advantages of it in many cafes were fo very evident, that the Emperor ordered it to be used in his Hungarian mines; and, as a recompenfe for his difcovery, gave him for ten years the third part of the favings arifing from its application, and four per cent. of this third part for the next twenty years. Even this did not defend him from being haraffed by his enemies; obftacles were ftill thrown in the way to prevent the introduction and fuccefs of his difcovery, and to defraud him of his well-carned recompenfe. Though he fuffered very much in the latter part of his life, yet this did not prevent him from continuing his literary purfuits. In 1790 he publifhed his Catalogue Methodique raifonné of the collection of fofils of Mifs Raab, which had been chicfly formed by his donations. work, elegantly printed in two volumes, was well received by the public:-and he was writing the Fafti Leopoldini, and a mineralogical work, when death put an end to his ufeful life, and to his fufferings. This Notwithstanding the varied advice of his phyficians, his difcafe continued. In fuch a ftate quacks find easy access to the fick. Who is not then ready to seize the nostrum of the bold pretender? One of thefe gave him a decoction which foon calmed his fufferings, and which he was affured would cure him in a few weeks. He continued the use of this for the last five months of his life: it really diminished his pains; but his friends obferved that his cheerfulnefs, which hitherto had not left him, diminished likewise, and that fpafms often attacked his upper limbs. On the 21ft of July, 1791, he was feized with fpafms and cold; the former foon fubfided on friction, but he loft his fpeech. On ne fubfequent days he had different attacks till the 28th, when he found himself better; but he was foon attacked again with fpafms, and in these he expired. Born was of a middle fize and delicate conftitution, dark complexion, black hair, and large black eyebrows. Wit and fatire, and a quick comprehenfion, were marked in his Bb 2 eyes; eyes; and his lively and penetrating genius appeared in his countenance. Befides being a good Latin claffic, he was mafter of moft European languages of note, and poffeffed a deal of general information nowife connected with those branches of fcience required in his profeffion. He was a great wit and fatirist, and a good companion, even under the fufferings of bodily pain. His too liberal and unguarded use of fatire made him many enemies. In his youthful days he wrote the Staats Perücke for the amufement of his friends; this was afterwards published without his knowledge. But nothing fhows more his talent for fatire than his Monachologia, which he published in 1783, juft when the Emperor Jofeph was making his reforms in the church. Indeed, at any other time fuch a fevere fatire on the monks would not have been permitted. They are characterifed thus: "Monachus. 66 Defcriptio. Animal avarum, foetidum, immundum, fiticulofum, iners, inediam potius tolerans quam laborem ;-vivunt e rapina & queftu; mundum fui tantuin caufa creatum effe prædicant; coeunt clandeftine, nuptias non celebrant, fœtus exponunt; in propriam fpeciem fæviunt, & hoftem ex infidiis aggrediuntur. Ufus. Terræ pondus inutile. Fruges confumere nati." And upon the order of Dominicans he fays-"Eximio olfactu pollet, vinum & hærefin* e longinquo odorat. Efurit femper polyphagus. Juniores fame probantur. Veterani, relegata omni cura & occupatione, gulæ indulgent, cibis fucculentis nutriuntur, molliter cubant, tepide quiefcunt, fomnum protrahunt, & ex fuis diæta curant, ut esca omnis in adipem tranfeat, lardumque adipifcantur: hinc abdomen prolixum paffim præfeferunt; fenes ventri cofi maxime æftimantur. Virginitatis facræ ofores in venerem volgivagam proni ruunt. Generi humano & fanæ rationi infeftiffima fpecies, in cujus creatione non fe jactavit auctor naturæ." The Archbishop of Vienna complained to the Emperor against this work; who replied, that it was only the idle and useless part of the fpiritual order which was attacked. This was feconded by his Defenfio Phyfiophili; and to this fucceeded his Anatomia Monachi. He wrote likewife a fatire on Father Hell, the aftronomer, by publishing a long Latin advertisement, full of irony, announcing a book written against the free mafons, in the name of this learned Jefuit. It must not be forgotten, that his house was always open to the travelling literati who visited Vienna; and that unprotected genius was always fure to find in him a friend and patron. He carried this perhaps too far, fo far as to ruin his eftate: probably the expectation of receiving a large income from the amalgamation, made him lefs attentive to œconomy in his domestic concerns; though I believe his infolvency was chiefly owing to ufurers and money-lenders, to whom he was obliged to have recourte to carry on his expenfive projects. Through thefe, though his patrimony was very confiderable, he died greatly in debt: this is the more to be lamented, as he left a wife and two daughters. As being inquifitors. NATURAL NATURAL HISTORY. On the Nature of the Diamond. By STR IR Ifaac Newton having observed that inflammable bodies had a greater refraction, in proportion to their density, than other bodies, and that the diamond refembled them in this property, was induced to conjecture that the diamond was of an inflammable nature. The inflammable fubftances which he employed were, camphire, oil of turpentine, oil of olives, and amber; thefe he called "fat, fulphureous, unctuous bodies;" and, ufing the fame expreffion refpecting the diamond, he fays, it is probably "an unctuous body coagulated." This remarkable conjecture of Sir Ifaac Newton has been fince confirmed by repeated experiments. It was found that, though the diamond was capable of refifting the effects of a violent heat when the air was carefully excluded, yet that, on being expofed to the action of heat and air, it might be entirely confumed. But, as the fole object of thefe experiments was to afcertain the inflammable nature of the dia mond, no attention was paid to the products afforded by its combuftion; be determined, whether the diaand it ftill, therefore, remained to mond was a distinct substance, or one of the known inflammable bodies; nor was any attempt made to decide this question, till M. Lavoifier, in 1772, undertook a feries of experiments for this purpose. He expofed the diamond to the heat produced by a large lens, and was thus enabled to burn it in clofe glafs-veffels. He obferved, that the air in which the inflammation had taken place had become partly foluble in water, and precipitated from lime-water a white powder, which appeared to be chalk, being foluble in acids, with effervefcence. As M. Lavoifier feems to have had little doubt that this precipitation was occafioned by the production of fixed air, fimilar to that which is afforded by calcareous fubftances, he might, as we know at prefent, have inferred that the diamond contained charcoal; but the relation between that fubftance and fixed air was then too imperfectly understood to juftify this conclufion. Though he obferved the refemblance of charcoal to the diamond, yet he thought that nothing more could be reasonably deduced from Bb 3 their their analogy, than that each of thofe fubftances belonged to the clafs of inflammable bodies. As the nature of the diamond is fo extremely fingular, it feemed deferving of farther examination; and it will appear, from the following experiments, that it confifts entirely of charcoal, differing from the ufual state of that fubftance only by its cryftallized form. From the extreme hardness of the diamond, a ftronger degree of heat is required to inflame it when expofed merely to air, than can eafily be applied in clofe veffels, except by means of a ftrong burning lens; but with nitre its combustion may be effected in a moderate heat. To expofe it to the action of heated nitre, free from extraneous matters, I procured a tube of gold, which, by having one end clofed, might ferve the purpose of a retort; a glafs tube being adapted to the open end, for collecting the air produced. To be certain that the gold veffel was perfectly clofed, and that it did not contain any unperceived impurities which could occafion the production of fixed air, fome nitre was heated in it till it had become alkaline, and afterwards diffolved out by water; but the foiution was perfectly free from fixed air, as it did not affect the tranfparancy of limewater. When the diamond was deftroyed in the gold veel by nitre, the fubftance which remained precipitated lime from lime-water; and, with acids, afforded nitrous and fixed air; and it appeared folely to confift of nitre, partly decompofed, and of aërated alkali. In order to estimate the quantity of fixed air which might be obtained from a given weight of diamonds, two grains and a half of small diamonds were weighed with great accuracy, and, being put into the tube, with a quarter of an ounce of nitre, were kept in a ftrong red heat for about an hour and a half. The heat being gradually increased, the nitre was in fome degree rendered alkaline before the diamond's began to be inflamed; by which means almost all the fixed air was retained by the alkali of the nitre. The air which came over was produced by the decompofition of the nitre, and contained fo little fixed air as to occafion only a very flight precipitation from lime-water. After the tube had grown cold, the alkaline matter contained in it was diffolved in water, and the whole of the diamonds were found to have been deftroyed. As an acid would difengage nitrous air from this folution, as well as the fixed air, the quantity of the latter could not, in that manner, be accurately determined. To obviate this inconveniency, the fixed air was made to unite with calcareous earth, by pouring into the alkaline folution a fufficient quantity of a faturated folution of marble in marine acid. The veffel which contained them, being clofed, was left undifturbed till the precipitate had fallen to the bottom; the folution having been previously heated, that it might fubfide more perfectly. The clear liquor being found, by means of lime-water, to be quite free from fixed air, was carefully poured off from the calcareous precipitate *. The veffel which was used on this *If much water had remained, a confiderable portion of the fixed air would have been abforbed by it. But, by the fame method as that defcribed above, I obferved, that as much fixed air might be obtained from a folution of mineral alkali, as by adding an acid to an equal quantity of the fame kind of alkali. occafion occafion was a glaís globe, having a tube annexed to it, that the quantity of the fixed air might be more accurately measured. After as much quickfilver had been poured into the glass globe containing the calcareous precipitate as was neceffary to fill it, it was inverted in a veffel of the fame fluid. Some marine acid being then made to pass up into it, the fixed air was expelled from the calcareous earth; and, in this experiment, in which two grains and a half of diamonds had been employed, occupied the space of little more than 10.1 ounces of water. The temperature of the room, when the air was measured, was at 55°, and the barometer stood at about 29.8 inches. From another experiment, made in a fimilar manner, with one grain and a half of diamonds, the air which was obtained occupied the space of 6.18 ounces of water; according temperature above mentioned, to be 695 parts of a grain. If we reduce the French weights and meafures to English, and then compute how much fixed air, according to this proportion, two grains and a half of charcoal would produce, we fhall find that it ought to occupy very nearly the bulk of 10 ounces of water. M. Lavoiffer feems to have thought that the aerial fluid, produced by the combuftion of the diamond, was not fo foluble in water as that procured from calcareous fubftances. From its resemblance, however, in various properties, hardly any doubt could remain that it confifted of the fame ingredients; and I found, upon combining it with lime, and expofing it to heat with phofphorus, that it afforded charcoal, in the fame manner as any other calcareous substance. to which proportion, the bulk of On the Action of Nitre upon Gold and ounces. The quantity of fixed air which was thus produced by the diamond, does not differ much from that which, according to M. Lavoifier, might be obtained from an equal weight of charcoal. In the memoirs of the French Academy of Sciences for the year 1781, he has related the various experiments which he made to afcertain the proportion of charcoal and oxygen in fixed air. From thofe which he confidered as moft accurate, he concluded, that 100 parts of fixed air contain nearly 28 parts of charcoal, and 72 of oxygen. He eftimates the weight of a cubic inch of fixed air, under the preffure and in the Platina. By the fame. From the Philofophical Tranfactions of the Royal Society of London. G OLD, which cannot be calcined by exposure to heat and air, has been alfo confidered as incapable of being affected by nitre. But, in the courie of fome experiments on the diamond, an account of which has been communicated to the Royal Society, I obferved, that when nitre was heated in a tube of gold, and the diamond was not in fufficient quantity to fupply the alkali of the nitre with fixed air, a part of the gold was diffolved. From this obfervation, I was induced to examine more particularly the action of nitre upon gold, as well as o enquire whether it would pro Bb 4 duce |