Description and chemical composition of manganese deposits during the deep-sea expedition of the streamer Valdivia in 1898-1899

These volumes are published under the editorship of Prof. Chun, the zoologist of Leipzig, who was leader of the expedition ; and Prof.

E. Philippi with the cooperation of Sir John Murray. The nature of the materials brought up at various points during the voyage is well illustrated by a series of plates, similar to those accompanying the Challenger volumes. Among the concretions from the Agulhas Bank were found phosphatic nodules containing 33 per cent, of calcium carbonate, 28 of calcium phosphate, 14.6 of calcium sulphate, and 4.8 of magnesium carbonate, with some ferric oxide, alumina, and silica.