This volume is a supplement to a well known treatise bearing the same title, which has already earned for itself a secure place among the reference books to be found in the chemist's library. Solubility relations of chemical compounds embrace research in many different lines. The compilation of certain data in the present volume is but another indication of the present trend of biochemistry; that is, the tendency toward an explanation of biochemical phenomena on a physicochemical basis. Among the many data included in the present volume are the solubility relations of the different calcium phosphates in diverse biologic mediums, and the solubility of carbon dioxide in chlorophyll. The solubilities of the various organic chemicals used in medicine are made available and some data are included on the solubility of various medicaments in blood serum. The book is essentially a reference book for the chemical specialist and will be found