Excerpt from The Problem of Age, Growth and Death Fig. 1. Photograph OF chevreul, taken on his one hundredth birthday. He was asked to write in an album and replied Que voulez vous que j'ecrive sur votre album. Je vais ecrire mon premier principe philosophique, cc n'est par moi, qui l'ai formule, c'eat Male branche On doit tendre avec effort a l'infallibilite, sans y pretendre. Chevreul was born Aug. 31, 1786 and died Aug. 9, 1889. For the privilege of using this portrait I am indebted to Dr. Henry P. Bowditch. To whom the interesting original belongs. 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.