Once Faraday had secured his post at the Royal Institution, his life-work was before him, and he became deeply engaged in scientific speculations, investigations and experiments of all kinds. The young man who had found and made opportunities when they were so distant and difficult, now made use of all that were so ready at hand. He did not confine himself to his laboratory work, however, but seems always to have felt that the contact of minds engaged along the same lines was the best possible way to be stimulated to knowledge. He applied and was admitted as member of the Philosophical Society of London, an association of some two score of men occupied with many things during the day, but interested in science, so far as they could get the books and the opportunities for its study. They met every Wednesday evening and discussed various subjects in science or, as they called it then, in philosophy, and they seem to have occupied themselves with many questions in the social as well as the natural sciences. These men, most of whom were older than Faraday, soon came to look up to him because of the depth and increasing breadth of his knowledge, and we have some emphatic expressions of their admiration for him. Faraday's earliest successful scientific investigation was accomplished in chemistry. This might have been expected, from the fact that he began his work with Sir Humphry Davy, whose principal scientific investigations had been concerned with chemistry. His own great scientific work was to be done in electricity. Even in the brief time that he devoted to chemistry, however, he succeeded in making some discoveries of deep significance. For instance, in his special study of chlorine, he demonstrated the existence of the two chlorides of carbon which had not hitherto been obtained. Above all, he impressed his personality upon methods in chemistry. He was the first to realize how much technics were to mean in the modern advancement of science, and he made methodic chemistry, in distinction from practical chemistry, the object of very special study. His work on _Chemical Manipulation_ did more to train successful students of chemistry and to make good investigators in this department of science than any other single work in his generation. It has continued to be of interest down even to our own time, and is well worthy of consultation by all those who are interested in chemistry as a science, and especially in original research in that subject.