526 Nitrogen in Cells 
Nitrogen. 
Kind of organism. 
Nicolle and 
Alilaire. Whee 
per cent per cent 
B.. proteus OUlgari s+ Pe ee oe ee 10.73 6.791 
Dy pinoy. Cees, vs 0 Slo Pe ae oe 8.28 11.55 
A TGH TS ey Pia sete y Sick: s te aan Oe eee eee 9.22 10.28 
COLON ko ari oe i ae ee 10.32 10.655 
BSPyOCUaNeUs dean cleo oe cee ae Pee eee 9.79 10.843 
METSUDITITS Sec. eG RE toe ei ee — 5.964 
SV EDLOLGBEUS cars <3 Reese See ee eee — 11.765 
< tuberculosis. Sir-Grien- aera ee, ne) AER — 9.27 
Chiorella vulgaris site te ae ee ee 3.96 —— 
Braysenterie liqueyacienss. 01 - e ee 8.89 = 
Le DNOCUIMONLO © 2c eae See At ek oe, Re ae ee ae 8.33 oe 
FEA DSILLOCOSLS: cssie hc, at Res eee Cn ee ae 9.55 
Ciainders: sis, S57) besa tan nt 3 eee eee 10.47 a 
SQPCINA GUEANRUGCA, Ae) eee a ee — 11.46 
Method. 
A battery of ten hard glass test-tubes was set up together 
with a sand bath and Bunsen burners to furnish the required tem- 
perature. Inverted funnels with bent stems connected with 
rubber tubes to a suction bottle were placed over the tubes to 
remove the fumes and exclude the dust. 
The bacteria used in the experiment were cultures of Bacillus 
diphtherie which had been isolated from the throats of persons 
suffering from the disease. These bacteria were grown on Loef- 
fler’s blood serum medium slants for 72 hours. It usually re- 
quired eight of these tubes to furnish enough material for one 
determination. The growth of organisms was removed without 
disturbing the solid medium, by a glass spade with rounded edges, 
made by flattening a small glass rod. The material was spread 
on a tared cover-slip and dried in a calcium chloride desiccator 
at 37°C. for 72 hours. 
On account of the small amount of the material obtainable 
frorh a reasonable number of tubes, the weighing was done on 
an assay balance which was sensitive to 0.000005 gm. The 
weighing glasses were the thin, 15 mm. square cover-slips used 
in bacteriological work. They were cleaned in concentrated 
