0.6[A] grm. taken. Reading on measuring tube = 114.6 c.c. NO. Barometer— 758 mm. Temperature—15° C.
[Footnote A: 0.5 grm. is enough in the case of gun-cotton.]
Since 1 c.c. NO = 0.6272 milligramme N, and correcting for temperature and pressure by the formula
760 x (1 + d^{2}) (d = .003665), for temperature 15° = 801.78,[A]
then
(114.6 x 100 x 750 x .6272)/(801.7 x. 6) = 11.22 per cent. nitrogen.
[Footnote A: See Table, page 244.]
The nitrogen in nitro-glycerine may of course be determined by the nitrometer, but in this case it is better to take a much smaller quantity of the substance. From 0.1 to 0.2 grm. is quite sufficient. This will give from 30 to 60 c.c. of gas, and therefore a measuring tube without a 100 c.c. bulb must be used.
EXAMPLE.
0.1048 grm. nitroglycerine taken gave 32.5 c.c. NO. Barometer, 761 mm. Temperature, 15° C.