The determinations reported in this paper were made with the hope of finding the distribution of common elements and minerals in the fractions obtained by mechanical separation of the several sizes of grains in a series of clays. A little chemical work done in the past few years has been found suggestive and is noted here before reporting the new work.
A composite sample of West Virginia clays was tested by both mechanical and chemical analysis in 1905.2 The United States Bureau of Soils has made a number of similar determinations on soils,3 but the proportion of silt and clay is small in loams, and the finer sizes were not separated in their work, whereas they are most important in the study of clays.4 Sven Odén has tested the composition of the fine clay fractions of a Swedish glacial deposit.5 Widman made a similar test of the fractions from . . .