This chemical mobilisation of a huge dye unit was, and could still be, practically invisible in operation. Not only was the process practically the same as azo dye production, but, as the compounds were not particularly poisonous in the intermediate stages, there was no risk to the workers, and no need to violate secrecy by indicating special precautions.
The final stage, the preparation of diphenylchlorarsine, the actual Blue Cross shell constituent, occurred at Hochst, which also carried out the first three stages, already outlined as occurring at Ludwigshafen and Leverkusen. The last stage was a simple one and was carried out in plant and buildings previously used for peace purposes.
The other substances employed provide further examples of this ease of production. Ethyl-dichlor-arsine was produced in homogeneously lead-lined vessels, identical with those used for diphosgene. Dichlor-methyl-ether presented difficulties which were solved by applying the German method of using tiled vessels.
The part played by the I.G. in the German chemical warfare organisation has already been outlined, and we have seen how the German Government was content simply to place its demands before the directors of the dye combine. The latter were left to choose the process and exploit it by making the best use of their organisation, which was done after reviewing the plant at their disposal in the different branches. An interesting feature of the production of war chemicals by the I.G. is thus revealed by examining the actual locality of the separate operations leading to any one of the individual poison gases. The attached table shows us how the production of any particular war chemical involved a number of stages, each of which occurred in a different factory. The directors of the I.G. simply chose a particular plant in a particular factory which was most suited for the operation concerned. They
{The table (spread over pages 162-163) are "raw OCR" feed! NEEDS FIXED!!!}
FIRST STAGE RAW WAR CHEMICAL MATERIALS FROM THE I.G. PROCESS FACTORY
Phenyl Carbylamine 1. Aniline Condensation of aniline Kalle Chloride 2. Chlorine with carbon bisul 3. Caustic phide to phenyldithio soda carbamic acid Mustard Gas 1. Carbon Preparation of Ethyl-Ludwigs dioxide lene from Alcohol hafen 2. Bleaching
powder 3. Sodium
sulphide 4. Hydro chloric
acid Diphenylchlorarsine I. Aniline Conversion of Diazo- Ludwigs 2. Sodium benzene to Phenylar- hafen