Excerpt from Bacteria in Milk and Artificial Refrigeration for Dairymen Milk when kept moderately warm soon changes so that it becomes unfit for food. These changes are produced mainly by the growth and development within Lthe milk Of microscopic plants, called bacteria, which break down some of the substances present in milk with the formation of other substances having different physical and chemical properties. Some Of the pro ducts thus produced may then react with other compounds pres ent in the milk so that the resulting changes may be and are extremely complicated and difficult to follow even by a chemist. The souring of milk is an example Of the best known and Simp lest change that takes place as a result of bacterial growth. In this case certain types Of bacteria break -up the milk-sugar into lactic acid (which gives sour milk its sour taste), and carbon dioxide. The lactic acid formed reacts with the casein of the milk, changing it chemically so that it becomes insoluble and the milk thickens and is said to lopper. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.