BERGMAN

bergman, torbern olof (1735-1784), swedish chemist and naturalist, was born at katrineberg, vestergotland, sweden, on the 20th of march 1735. at the age of seventeen he entered the university of upsala. his father wished him to read either law or divinity, while he himself was anxious to study mathematics and natural science; in the effort to please both himself and his father he overworked himself and injured his health. during a period of enforced abstinence from study, he amused himself with field botany and entomology, to such good purpose that he was able to send linnaeus specimens of several new kinds of insects, and in 1756 he succeeded in proving that, contrary to the opinion of that naturalist, _coccus aquaticus_ was really the ovum of a kind of leech. in 1758, having returned to upsala, he graduated there, and soon afterwards began to teach mathematics and physics at the university, publishing papers on the rainbow, the aurora, the pyroelectric phenomena of tourmaline, &c. in 1767 johann gottschalck wallerius (1709-1785) having resigned the chair of chemistry and mineralogy, bergman determined to become a candidate, though he had paid no particular attention to chemistry. as evidence of his attainments he produced a memoir on the manufacture of alum, but his pretensions were strongly opposed, and it was only through the influence of gustavus iii., then crown prince and chancellor of the university, that he gained the appointment, which he held till the end of his life. he died at medevi on lake vetter on the 8th of july 1784. bergman's most important chemical paper is his _essay on elective attractions_ (1775), a study of chemical affinity. in methods of chemical analysis, both by the blowpipe and in the wet way, he effected many improvements, and he made considerable contributions to mineralogical and geological chemistry, and to crystallography. he also made observations of the transit of venus in 1761, and published a _physical description of the earth_ in 1766. his works were collected and printed in 6 vols. as _opuscula physica et chemica_ in 1779-1790, and were translated into french, german and english. bergschrund (ger. _berg_, mountain; _schrund_, cleft or crevice), a gaping crack in the upper part of a snowfield or glacier, near the rock wall, caused by the glacier moving bodily away from the mountain-side as the mass settles downwards. the crack is roughly parallel to the rock-face of the upper edge of the glacier basin, and extends downwards to the solid rock beneath the glacier where at the bottom of this huge crevasse there are blocks of ice, and large pieces of rock torn off by the lower portion of the glacier from the rock wall and floor.