Dr. Eyre has subjected his work to a most searching revision. Indeed, so thorough was his revision that the entire book, enlarged by some 150 pages and 50 illustrations, had to be reset from cover to cover. He has included all the latest technic in every division of the subject. His thoroughness, his accuracy, his attention to detail make his work an important one. He gives clearly the technic for the bacteriologic examination of water, sewage, air, soil, milk and its products, meats, etc. And he gives you good technic—methods attested by his own large experience. To any one interested in this line of endeavor the new edition of Dr. Eyre's work is indispensable. The illustrations are as practical as the text.