60 PROTEIN POISONS 



thought' that this might be either glycogen or amylodextrin. 

 He also obtained a substance that he considered a mixture 

 of much amylodextrin and a little /3-amylose. It is easily 

 extracted from the cell with water. It may be remarked 

 here that our researches have shown that substances 

 removable from the cell by physical solvents constitute no 

 part of the actual cell protein. The carbohydrate in the 

 essential part of the cell is a constituent of the protein 

 molecule. All carbohydrates, fats, waxes, and inorganic 

 salts that may be washed out of the cell substance are 

 either no part of the cell proper or result from autolytic 

 changes in the cell molecules. 



Levene 1 obtained a glycogen-like body from the tubercle 

 bacillus. The cell substance was extracted with salts, or 

 better, with alkali, the albumins removed from the extract 

 with picric and acetic acids, the nuclein and carbohydrate 

 carried down together with alcohol, and then separated by 

 means of copper chloride. The glycogen thus obtained is 

 soluble in water, gives the iodine color test, and reduces 

 Fehling's solution after being boiled with dilute mineral 

 acid. Emmerling 2 prepared chitin or a closely related body 

 from the zooglea of bacterium xylinum. From 110 grams 

 of moist, impure material he secured 0.2 gram of crystal- 

 line glucosamine hydrochloride. Helbing 3 concluded that 

 chitin makes up a large part of the tubercle bacillus, and 

 to this constituent he attributed the peculiar staining 

 properties of this organism. He was clearly wrong in this 

 inference. All the early work on the carbohydrate con- 

 stituent of the bacterial cell, when the material was grown 

 on media containing carbohydrate, must be regarded as not 

 possessed of practical value. 



Fat, Wax, etc. In the earlier studies of the chemistry 

 of bacterial cells it was assumed that the alcoholic and 

 ethereal extracts consisted of fats exclusively. Kramer 4 



1 Loc. cit. 2 Berichte, 1899, xxxii, 541. 



3 Deutsch. med. Woch., xxvi, Vereinsbeilage, 1900, 133. 



4 Arch. f. Hygiene, 1891, xiii, 71; ibid., 1893, xvi, 151; ibid., 1895, xxii, 

 167; ibid., 1897, xxviii, 1. 



