The Cellular Reactions to Acetone-soluble Fat from Mycobacteria and Streptococci

1. The acetone-soluble fat of tubercle bacilli produces a profound cellular reaction when injected into normal animals. The reaction involves every type of connective tissue cell. Hemorrhage, formation of adhesions and of tubercular tissue occur. The extent of the reaction is roughly proportional to the amount of material injected. 2. The reaction induced by the lipoid is much less extensive and much simpler when the material is neutralized with alkali. Neutralization of the acetone-soluble fat, or of phthioic acid, does not diminish the tuberculogenic property. 3. Acetone-soluble fat from streptococci is likewise extremely irritating but does not produce tubercular tissue.