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BERGMANN, Torbern, in Biography, profefrorof che- 

 iniftr)' at Uufal, was born at Catheiineberg, ia Weft Goth- 

 land, March 20th 1735; and after having liniflied the Firft 

 coiirfe of his education, entered at the univeriity of Upfal. 

 His application, particult'.rly to the ftudy of n-.athcmatics and 

 nat\iral philofophy, was fo intenfe, tjiat his lifahh was endan- 

 gered ; and as thefe fcienccs afford no peculiar profpeft of emo- 

 lument, a relation, who had the charge of him, difcouraged his 

 profecution of them, and rendered it neceffaiy for him to con- 

 ceal the- books which siiillcd hi;n in his favourite ftudies. 

 At the clofe of a year hii heakh was fo much impaired, that 

 the reftoration of it required an intermiffion of his application, 

 and a courfe cf excrcife, v»hich obliged him to return to his 

 family. H'.s hours of relaxation were, however, occupied in 

 the ftudy of botany and entomology, and his difcoveries in 

 the laft of thefe fcienccs were communicated to Linnsus. 

 As foon as his health was re-eftablifhed, he returned to the 

 univcrfity, with ample permifTion to purfue thofe ftudies which 

 were moft agreeable to hia inclination. Befides mathematics 

 <!ud natural philofophy, he direfted his attention to natural 

 biftor^-, under the patronage of Linnsus ; and began with a 

 memoir on the nature of the fubftance found in certain 

 waters, and called coccus aquaticus, which he found to be 

 the egg of a leech, including 10 or 12 young. This was 

 followed by other memoirs on the hiftory of infefts which 

 attack fruit-trees, and the means of preventing their ravages; 

 and he propofed a method of ciaffing th.ie infects from the 

 form of the larva, in which ftate the deilruftion of noxious 

 infedf s is moft efFential. About this tim.e, the famous Svvedifti 

 naturalift teftified his ellcem of Bergmann's charadler and 

 talents, by giving his name to a new fpecies of infefts. In 

 1761, Bergmann was appointed profeftbr of mathematics 

 and natural philofophy in the univcrfity of Upfal ; and both 

 before and after this time he enriched the volumes of the 

 Swedifii afts with feveral papers on pliilofophical fubjefts. 

 Kis paper, containing " t\. Review of the feveral explana- 

 tions which Natural Philofophers have given of the Rain- 

 bow," was pubiiftied in 1759; and in 1760, he pubhfhcd 

 fome thojghts " On the origin of thofe meteors, which are 

 not iccoTipanied by any fenfible found or explofion," and 

 alfo " On the opinions held by Philofophers relating to the 

 Twilight," to which is prefixed an account of Mairan's 

 " Anticrepnfculum," or tl'.at of the horizon oppofite to the 

 fun. In 1761, and in 1762, profeftbr Bcrgmann wrote on 

 the fubjeft of eleftricity, in confequcnce ol acorrefpondcnce 

 with Mr. Wilfon ; and particularly on the eleftrical quality 

 of Iceland Ci yftal, and double refrafting fpar. H:s remarks 

 on the tenthredo, or faw-fly, ftiewing how to diiliiiguifti be- 

 tween the caterpillars of this infect and thofe of the butterfly 

 and moth, and c'ifcoverin g the feet in the latter to be never more 

 than 1 5, and thofe of the tenthredo aUvays exceeding that num- 

 ber, were pubhfned in 1763 ; and the lame year produced the 

 unlatisfaftory rcfult of forr.e eleflrical experiments, made with 

 filk of various colours. In i 764, the proiefior wrote a paper 

 to afcertain, from a number of obfcrvations, the height in the 

 atmofphere at which the aurora bortalis exifts (fee Aurora 

 Borealis) ; and in 1765 and 1766, he wrcte again on elec- 

 trical fubjefts ; and principally on the property and laws of 

 elcftricity in the tourmalin, which had been relerred to his 

 examination by the Royal Academy of Sciences at Stock- 

 holm. At this time it does not appear that the fubjeft of 

 chemiftry had em.ployt.d much of Mr. Bergmann's attention; 

 however, in 1767, on the refignation of Wal erius, he was 

 chofen to fucceed him as profeftbr of chemiftry and metal- 

 lurgy. This appointment was much cppofcd by the party 

 of the former profeftbr, united wiiu others who envied 

 Bergmann's rifing merit ; and the:r oppofition was fupported 

 by fome fevtre criticifms on two pap'.rs, which the prokflbr 



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publifiied at this time, relating to the depuration of alum;- 

 in which he recommends the ufe of argillaceous earth, and 

 propofes tobaico-pipe clay, inftead of alkali, to free it from 

 the vitriol. But the prince royal of Sweden, who aftenvards- 

 fncceedcd to the throne, and who was then chancellor of the 

 univcrfity of Upfal, determined the difpute, and fixed him in 

 the profeffor's chair. With enlarged views of the praftical 

 importance and utility of chemiilry, of what had already been 

 performed in this department of fcieice by preceding authors, 

 and of what yet remained to be done, Bergmann profecutcd 

 his chemical rcfearches, and by a combination of expcritnental 

 analyfis with mathematicsl reafoning, he extended and im- 

 proved this fcience by a variety of valuable difcoveries and 

 obfcrvations. In order to purfae his experiments and en- 

 quiries with the greater facility, and to communicate the re- 

 fult with advantage to his pupils, he formed, near his labo- 

 ratory, a cabinet, in which al! the miijj-ral fubftances were 

 ranged in order, together with the produfts of thofe experi- 

 ments which had afcertaintd their compofition. Another 

 colieftion exhibited all the minerals of Sweden, arranged ac- 

 cording to the places where they are found. In a third, were 

 exhibited models- of the various machines and apparatus by 

 means of which thefe fubftances were converted into ufeful 

 articles, which articles were placed near the materials from 

 which thty were formed. From this fyftematical airange- 

 ment Bcrgmann derived peculiar advantage in his profeflion 

 as a teacher. While he excelled as a profeftbr of chemiftry 

 and mineralogy, and devoted much of his time to this occu- 

 pation, he was aftively and inceftantly employed in makinjj 

 difcoveries which have placed him in the firft rank of philo- 

 fophical chemifts. He examined tne carbonic acid, difco- 

 vured by Black, and denominated fixed air, in its feveral pro- 

 perties and habitudes. Nickel, manganefe, the magnefian 

 earth, and barytes, which were newly difcovered fubftances, 

 were particularly inveftigated by Bergmann, and afforded 

 materials for regular and perfpicuous treatifcs. The acid 

 obtained from fugar, and many other vegetables, by the ab- 

 ftrartion of the nitric acid, and thofe acids which are ob- 

 tained from arfenicj molybdena, fluor fpar, and tungften, 

 were difcovered either by Iri ; felf or fome of his difciples ; 

 and to him we are indebted for leading the way in the invefti- 

 gation of their properties, and for afcertaining many intereft- 

 ing phenomena attending their comibinations. From, him we 

 learn, that iron contains a number of foreign admixtures, 

 chiefly of a m.ctaUic nature, and that the three ftates of crude 

 iron, and malleable iron, and ft.eel, principally depend upon 

 the greater or lefs abundance cf carbon. In his analyfis of 

 waters, he added, to the re-agents before ufcd, other fub- 

 ftances more effeftual, and whilft he evinced the imperfec- 

 tion of this method, he rendered it much more accurate. 

 He alfo afcertained the quantities of produfts, without fepa- 

 rating them from all their combinations ; and in this way he 

 inters the quantity of metal from the weight of precipitate it 

 affords, by tl'.e addition of an alkali, or fome other known 

 fiibftance, from tables founded on former experiments. He 

 likewife analyfed the precious ftones, known by the name of 

 gems, anddevifed peculiar methods for feparating them into 

 the known earths in determinable proportions. Profeftbr 

 Bergmann evinced the nectffity and utility of performing 

 dccimaliic operations in the humid way, or by an analyfis, in 

 which liquid folvents are ufed ; and he alfo exhibited the ad- 

 vantages of the proccfs by fire, applied to materials in minute 

 portions, by means of the blow-pipe, either upon a piece of 

 charcoal, or in a fpoon of pure filver- This mode of exa- 

 mining mineral fubftance?, united with that of the habitudes 

 which they exhibit, with a tew fimple le-agents, facilitated 

 the ctaftificatiorr of them, according to their chemical pro- 

 perties ; a method adopted by this ingenious cheinift, witli, 



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