58 
THE CHEMISTRY OF BACTERIA 
The phosphorus content of the medium in these experiments, as 
shown in the above table, was varied ahnost twenty times, but in the 
bacterial organisms it varied scarcely three times. The variation in 
chlorine content was somewhat greater. 
Even as important an element as nitrogen is subject to rather wide 
variations in bacteria, as Cramer^ and Lyons- have showii. The 
following tables summarize Cramer's results. They were obtained 
by growing certain bacteria mentioned specifically below^ on a medium 
consisting fundamentally of 1.5 per cent agar, to which were added 
various substances, as indicated in the tables, respectively Media 
A, B and C. The general procedure was to grow the bacteria at 
37° C. for several days, to wash them off with salt solution, to free 
them from adherent media by centrifugalization and washing, to dry 
the washed organisms in vacuo to constant weight, and to analyze 
the drv residue for extractives and ash. 
CRAMER, 
Medium. 
Nitrogen substance. 
Ether-alcohol 
extractives. 
Ash. 
A 
B 
C 
ABC 
A 
B C 
Oigauism. 
Pfeiffer bacillus . . 
BacUlus H-28 . . 
Pneumonia bacillus 
Rhinoscleroma bacillus 
G6.6 
73.1 
71.7 
68.4 
70.0 
79.6 
79.8 
76.2 
53.7 
59.0 
63.6 
62.1 
17.7 14.63 24.0 
16.9 17.83 18.4 
10.3 11.40 22.7 
11.1 9.06 20.0 
12.56 
11.42 
13.94 
13.45 
9.10 9.13 
7.79 9.20 
10.36 7.88 
9.33 9.44 
Organism. 
Pfeiffer bacillus 
Bacillus No. 28 
"Thread bacillus 
Nitrogen- 
containing 
substance. 
LYONS. 
Ether 
extractives. 
Alcohol 
extractives. 
62.75 58.88 45.881.683.50 2.67 12.1'; 
71 . 81 59 . I2I46 . 25'3 .323 . 84!2 . 84 1 1 . Sf 
61 . 06|44 . 3 1133 .251. 742 . 24; 1 . 87i 18 . 4( 
I I i 1 ! ! 
17.30 
15.19 
21.80 
29.607.16 
22.78:6.51 
27.5018.09 
2.79'3.09 
3.664.18 
4.503.02 
Medium A agar, 1.5 per cent.; peptone, 1 
Medium B agar, 1 .5 per cent.; peptone 5, 
1.5 per cent.; peptone, 1 per cent 
iTicuiuiii u a.^a.1, 1 .5 per cent.; peptone 5, per cent. 
Medium C agar. 1.5 oer cent.: oeotone. 1 oer cent 
5 per cent.; peptone 5, per ^^.... 
5 per cent.; peptone, 1 per cent.; glucose, 5 per cent. 
It will be seen that the nitrogen content of the bacteria grown in a 
medium containing nitrogen plus carbohydrate is almost 25 per cent 
less than the nitrogen content in the same organisms grown in the 
same nitrogen medium but with no carbohydrate. The nitrogen 
content is greatest in the carbohydrate-free medium, the extractives 
Arch. f. Hyg., 1893, 16, 151. 
Ibid., 1897, 28, 30. 
