64 PROTEIN POISONS 



prepared in our laboratory, makes substantially the follow- 

 ing statement. The cell substance, prepared by the method 

 already described, takes up moisture readily and holds it 

 tenaciously, but may be dried to constant weight by heating 

 small amounts in a steam-drying oven for many days at from 

 85 to 95. If the temperature falls to 60, it may absorb 

 moisture even in the oven. One sample was heated to 105 

 during working hours for three days and kept in a desiccator 

 during the intervals; it increased in weight. Drying in 

 vacuo over sulphuric acid is, on the whole, the most satis- 

 factory method, although it may require days and even 

 weeks. 



The dried cellular substance burns with a flame, forming 

 volatile and liquid products, giving off odors characteristic 

 of nitrogen compounds, and finally leaving a greenish ash. 

 Two determinations gave the following results: 



0.346 gram gave 0. 025)0 gram of ash, or 8.55 per cent. 

 0.496 gram gave 0.0431 gram of ash, or 8.68 per cent. 



Values reported for other bacteria vary from 3 per cent, 

 in putrefactive organisms to 13 per cent, in prodigiosus, or, 

 by using special media, to nearly 30 per cent, in the cholera 

 bacillus; while in the tubercle bacillus the ash has been 

 found to vary from 1.77 to 5.92 per cent, according to 

 conditions. The ash from the colon bacillus, as we have 

 prepared it, contains sodium, potassium, small amounts of 

 calcium, aluminum, copper, and phosphates. A slight 

 residue insoluble in acid is probably silica. Sulphate is 

 present in so small an amount that it may escape detection, 

 and chloride has not been found. In comparison with the 

 data obtained with other bacteria, these findings are note- 

 worthy only in the absence of magnesium, and in the 

 presence of copper and aluminum. Presumably the former 

 comes from the tanks and the latter from the agar. 



Phosphorus was the only constituent of the ash quanti- 

 tatively determined. The ash was dissolved in nitric acid, 

 the phosphate precipitated with ammonium molybdate, 

 dissolved in ammonia, precipitated with magnesia mixture, 



