The Development Division had its origin in the research laboratories of the National Carbon Company and of the National Lamp Works of the General Electric Company. Both of these companies knew charcoal, and they were asked to produce a satisfactory absorbent charcoal. The success of this undertaking will be seen in the chapter on Absorbents. After a short time all the laboratory work was taken over by the National Carbon Co., while the developmental work was assigned to the National Lamp Works. When the final organization of the Chemical Warfare Service took place, the National Carbon Laboratory became part of the Research Division, while the National Lamp Works became the Defense Section of the Development Division. The Development Division may be considered as having been composed of the following sections: 1. Defense 2. Offense 3. Midland 4. Willoughby 5. Special Investigation. The work of the Defense Section consisted of the development of a charcoal suitable for use in gas masks, and its manufacture. While the details will be given later, it may be mentioned here that three weeks after the organization of the Section (April 28, 1917) the furnaces of the National Carbon Company were turning out cedar charcoal, using a straight distillation procedure. Cedar was selected from a large variety of materials as giving the highest absorptive value against chlorine. But phosgene and chloropicrin were also being used, and it was found that the cedar charcoal was not effective against either. Proceeding on a definite hypothesis, fifty materials were investigated to find the charcoal with the highest density. Cocoanut hulls furnished the raw material, which yielded the most active charcoal. By a process of air activation a charcoal was obtained which possessed high absorptive power for such gases as chloropicrin and phosgene. Later this air process was changed to one in which steam is used; the cocoanut shell charcoal activated with steam was given the name “Dorsite.” Complete apparatus for this air process was installed at the plant of the Astoria Light, Heat & Power Company, Long Island City, and the first charcoal was prepared during September, 1917. This was followed by a large amount of experimental work, relating to the raw material, the method of activation, and the type of furnace used. Because of the shortage of cocoanut hulls, it later became necessary to use a mixture of cocoanuts with cohune nuts, apricot and peach pits, cherry pits and vegetable ivory. Another substitute for cocoanut charcoal was found in a steam activated product from high grade anthracite coal, called “Batchite.”