With these admirable auxiliaries, Bergman entered upon his ardent career. Exempted from the preju. dices of theorists, and conducted by the torch of geometry, he began by repeating all the leading ex periments in chemistry ; he attended carefully to the various minute circumstances which seemed to affect the results ; lie marked the legitimate conclusions which his experiments authorised ; and,.by thus car rying into chemistry the principles of the philosophy of Bacon, he was rewarded by a variety of the most brilliant discoveries.
In examining the carbonic acid, or fixed air, which _Dr Black had discovered in the composition of al kalis and calcareous earths, he found that it was a particular acid, and called it the aerial acid: By distilling sugar with nitrous acid, he obtained from it a very strong acid, differing from all others in its pe culiar affinities, and which he also found to exist in honey, gum-arabic, in all the saccharine substances, and also in several animal products. He discovered likewise three new acids, viz. that of- molybdena, that of tungstcin, and that of phosphate of iron. The subject of earths next engaged his attention. He made numerous experiments on barytes ; he chewed, that magnesia was not a calcareous sub stance, as had been generally supposed ; and he pro. ved, that silex differed from all other earths, and par ticularly from argil.
In the year 1773, Bergman published a memoir on crystallization, in which he skewed. how.the va rious forms of crystals could arise from a simple pri mitive form, and how this primitive form could be determined by the dissection of the crystal. This admirable theory, of which Bergman has laid the foundation, has been carried to great perfection by• the Abbe Hauy, and the Count de Bournon.
On the analysis of mineral waters he published no fewer than six dissertations, which Macquer ranks among his most valuable productions. By employ ing new re-agents, lie gave a high degree of perfec.- ' tion to this kind of analysis. Instead of determi ning the qua1itities of the ingredients, by endeavour ing to obtain them singly, he endeavoured to find the weight of one of the 'ingredients when combined with some well-known substance which he employed for this particular purpose. He examined also the Composition of aerated and sulphureous•waters ; and. he was the first who pointed out the method of form ing artificial mineral waters.
His experiments on tartrate of potash and antimony, conducted him to the same'results which had been ob tained by Messrs Macquer and Lasonne ; and in his analysis of volcanic produCts, of which numerous and valuable specimens had been brought to Sweden by Messrs Ferber and Troil, he exhibited a particular ingenuity, and detected the various operations of na ture in the formation of these interesting substances.
In the analysis of many simple substances, and of several chemical compounds, he employed the blow. pipe with singular success. The composition of pre cious stones had hitherto been unknown, but, in the hands of Bergman, they submitted to an accurate analysis. With the simple apparatus of a blowpipe, a piece of charcoal, a small quantity of soda, and a little borax, he found that alumine, mixed with a pOrtion of silex, of lime, and of iron, was the base of emeralds, sapphire, topaz, hyacinth, and ruby ; that the proportional quantity of silex was succes sively increased in grenat, schorl, tourmaline, zeolite, quartz, and rock crystal ; and that gems were partly connected with siliceous stones, and partly with alum.
The researches of Bergman into the composition of metals and metallic oxides ; his analysis of nickel and zinc ; his explanation of the fulminating proper ty of several oxides of gold ; his inquiries respecting crude iron, malleable iron, and steel, in which he sheaved, that the various states in which iron appear ed was owing to the admixture of phosphate of iron; manganese, and many foreign substances, chiefly me tallic ; his labours in the mines of West Gothland ; his method of forming of a durable nature ; his investigations respecting the combination of mer. cury with muriatic acid ; respecting the analysis of calculi and asbestos ; and respecting sulphuretted an timonial preparations,—all these various labours can only be mentioned in this short sketch of his life.
The subject of elective attraction, which Geo& froy had begun in 1718, was resumed by Bergman with wonderful success. In order to complete this laborious undertaking, he calculated that no fewer than 30,000 experiments would be necessary ; but finding that his health was unfit for such enormous labour, he arranged the materials which he had col; lected, and published very accurate and extensive tables of elective attractions. These tables were the first that contained the laws of affinities as they are observed in operating by the dry way. He has re presented, by formnlm, all the chemical operations, the results of which form the basis of the table ; and he has exhibited, at one view, the substances upon which he operated, the method employed, and the result of the operation. In his work on elective attraction, and in that on metallic precipitates, he has explained all the phenomena by the various mo difications of the principle of phlogiston ; but though the existence of this principle has been completely exploded by the discoveries of Lavoisier, these, and his other works, will long continue to be resorted to by chemists, as the most valuable repositories of die mical facts.