GEOLOGICAL SURVEY OF MARYLAND.

다국어 초록 (Multilingual Abstract)

The first trials that were made rwith the black marl are those of Mr. Raisin Jones, at the head of Churn creek. The micaceous black sand, the composition of which was given in a former report, was in the first trial of it used fresh from the bank and liberally applied to a field in preparation for corn; it proved injurious, no doubt in consequence of the decomposition of the pyrites it contained, which must have given rise to the formation of sulphuric acid, under circumstances that prevented its immediate neutralization by the alkaline substances likewise contained in the sand.