THE ROYAL ARTILLERY INSTITUTION. 
391 
22*57 cubic centims. iodine solution; hence, according to the formula 
OTTf) Q2 (~)2 
s= a -j-= £, in which £=22*57, a= 0*000517; this litre contained 
0*1746 grm. hyposulphite of potash, and the entire residue 1*0476 grm. of 
this salt. 
4. Sesquicarbonate of Ammonia . According to Bunsen's method, a litre 
of the liquid was boiled with caustic potash, the distillate passed into a 
solution of hydrochloric acid of known strength, and the hydrochloric acid 
which had not been changed to chloride of ammonium determined with a 
standard ammonia solution. I found a = 0*04853, the quantity of hydro¬ 
chloric acid taken; ^=19*87, the number of divisions of an ammoniacal 
liquid which would have saturated a volume of hydrochloric acid equal to 
that taken with ^=41*30 divisions of the burette. Using the formula 
^ == 2NH^O,3CQ^ aff—t), j f oun( j * n t ^ e j lit re the sesquicarbonate of 
ammonia to be 0*041275 grm.; hence 0*9908 grm. corresponds to the 
entire quantity of sesquicarbonate of ammonia. 
5. Carbonate of Potash. Subtracting the carbonic acid in the sesqui¬ 
carbonate of ammonia = 0*5541 grm. from the total quantity found (2), 
= 2*8337 grms., there remains a quantity corresponding to the carbonate of 
potash =2*2796 grms. Hence the entire residue contains 7*1498 grms. 
carbonate of potash. 
6. Sulphate of Potash . A litre of the liquid mixed with chloride of 
barium gave 3*0244 grms. sulphate of baryta, which corresponds to 2*2683 
grms. sulphate of potash for one litre of liquid, and 13*6100 grms. for the 
whole residue. 
7. Potash. To determine the entire quantity of potash contained in the 
various salts, a litre of the liquid was carefully evaporated to dryness with 
sulphuric acid and ignited in a platinum vessel. 3*8466 grms. of sulphate 
of potash were thus obtained, corresponding to 2*0786 grms. of potash. 
Hence 100 grms. of ordnance powder contain 33*85 grms. of potash, which 
agrees closely with the result of the direct analysis of the powder. After 
finding, by direct observation, that 36*8366 grms. of the powder furnished 
7621*9 cubic centims. of gas, the composition of the products of combustion 
of this powder may be stated as follows— 
Sulphate of potash .. 13.61 
Carbonate of potash . 7‘14 
Hyposulphite of potash. 1'04 
Sulphide of potassium . 0*04 
Charcoal . 0*94 
Sulphur . 1*73 
Sesquicarbonate of ammonia. 0'99 
Nitrogen.. 3*60 
Carbonic acid. 6*40 
Carbonic oxide . 0-97 
Hydrogen . 0-04 
Sulphuretted hydrogen. 0-10 
Marsh-gas . 0*16 
Loss. 0*07 
36-82 
in which sulphur and charcoal are calculated from the deficiency. 
[vol. III.] 
M M 
