528 Nitrogen in Cells 
aspirated with ammonia-free air into 0.1. N sulfuric acid. The 
acid solution containing the ammonium sulfate was Nesslerized 
and compared with a standard solution of ammonium sulfate 
similarly Nesslerized, by means of the Duboscq colorimeter. A 
convenient strength of standard to use, if the quantity digested 
is about 5 mg., contains an ammonia equivalent of 0.0000025 gm. 
of nitrogen per cc. With every set of determinations two blanks. 
were run and the average of these was subtracted from the nitrogen 
found. 
The results of sixteen separate determinations are given in 
Table I. 
A nitrogen determination was-made on the Hoffmann ba- 
cillus, a diphtheroid organism, by this method with the results 
as recorded in Table II. 
TABLE II. 
Nitrogen Content of Bacillus hoffmannt. 
Cover-glass and dry Net weight of 
WeEtera Dry bacteria. niteogen: Nitrogen. 
gm. gm. a gm. per cent 
0.074110 0.002900 0.000277 9.6 
0.075590 0.003730 0.000356 9.5 
0.100210 0.006235 0.000600 9.6 
0.071810 0.009890 0.001020 10.3 
In order to determine the accuracy of the method, a macro- 
Kjeldahl determination was made on a larger quantity of the 
dried diphtheria bacteria with the following results: 
NO. Pin cent Vb eee ee Eien ee ee ene eee 7.9 per cent nitrogen. 
ete Ea hee re Ghee tern oes Sly ea as 
SUMMARY. 
In summing up the results of these determinations the following 
points seem important: 
1. The nitrogen content of Bacillus diphtherie is 
per cent 
Regular’ Kjeldahlmethod 128.2% Sacre. ce ee cee eee 8.0 
Micro-Kjeldahl method). (222e2e5. oe eee 8.35 
