*baum*

a. Designating or conforming to either of the scales used by the French chemist Antoine Baumé in the graduation of his hydrometers; of or relating to Baumé's scales or hydrometers. There are two Baumé hydrometers. One, which is used with liquids heavier than water, sinks to 0° in pure water, and to 15° in a 15 per cent salt solution; the other, for liquids lighter than water, sinks to 0° in a 10 per cent salt solution and to 10° in pure water. In both cases the graduation, based on the distance between these fundamental points, is continued along the stem as far as desired. Since all the degrees on a Baumé scale are thus equal in length, while those on a specific-gravity scale grow smaller as the density increases, there is no simple relation between degrees Baumé and specific gravity. However, readings on Baumés scale may be approximately reduced to specific gravities by the following formulæ (x in each case being the reading on Baumé's scale): (a) for liquids heavier than water, sp. gr. = 144 ÷ (144 - x); (b) for liquids lighter than water, sp. gr. = 144 ÷ (134 + x). [ Webster 1913 Suppl. ]