1909-10.] Composition and Character of Oceanic Eed Clay. 201 
cannot be wholly debited to the superjacent ocean, since much of it must 
have been derived from the volcanic mother-substances of the Red Clay 
itself. A not less serious item in the inorganic economy of the ocean would 
seem to be the adsorption by bottom-deposits of magnesia, the bulk of 
which must certainly represent a net withdrawal from the salts dissolved 
in the ocean. 
{Issued separately February 1 , 1910 .) 
