Excerpt from Fish Isinglass and Glue Collagen, the mother substance of gelatin, is an albumiid which occurs to a large extent in vertebrates and also in the flesh of cephalopods. It is the chief constituent of the white fibrils of connective tissue and is also found in bones, cartilages, ligaments, fish scales, etc. Collagens of different origins are t of identical composition; however, all show the characteristic albumiid property of being insoluble in water and the ordinary protein solvents. The most interesting and commercially important property of collagen is its power to be converted into gelatin by heating with water alone or in the presence of dilute acids. On the other hand, if gelatin is heated to 130 C.it is transformed back into collagen, so that there is a very intimate relation between the two substances. For practical purposes we may consider gelatin to be collagen which has been converted into a soluble form by combination with water. (Other changes have been ted, such as the evolution of ammonia, when collagen is treated with water.) 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 techlogy 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.