The seventh edition of this laboratory manual emphasizes once more the valuable service that the American Public Health Association renders by the establishment of committees to prepare such treatises. The last edition appeared in 1934. The present volume contains the newest approved methods for the bacteriologic and chemical examination of dairy products and a description of the bio-assay of vitamin D milk. In the appendix there are descriptions of several methods for testing by the phosphatase technic to determine whether milk has been properly pasteurized. None of the four methods described have been approved as a standard procedure, but the descriptions provided will afford various laboratories an opportunity to subject one or more methods to a thorough investigation.
It is noted with interest that the direct microscopic method for the examination of milk and cream for bacteria is described. This test permits the recognition of milk or cream with high