BY ARCHIBALD ROBINSON WARD, B. S. A., D. V. M.

Assistant Professor of Bacteriology and Director of the State Hygienic Laboratory,
University of California, Berkeley, California.

WITH TWO CHAPTERS

BY MYER EDWARD JAFFA, M. S.

Professor of Nutrition and Director of the State Food and Drug Laboratory,
University of California.

WITH SEVENTEEN ILLUSTRATIONS

LIBRA

OF THE

UNIVERSITY

OF

ITHACA, N. Y.

TAYLOR & CARPENTER

1909