228 GUN-COTTON AND GUNPOWDER. 
The results of the analyses were as follows :— 
‘1. Sulphide of potassium.—The entire filtered liquid was digested in three 
large boiling flasks with well-ignited oxide of copper, thereupon filtered, and 
the residue dissolved in fuming nitric acid. Treated with nitrate of baryta, 
it gave 0.1015 grammes of sulphate of baryta, which corresponds to 0.0478 
grammes sulphide of potassium in the residue of 36.8366 grammes powder. 
. The liquid filtered trom the oxide of copper was made up to 6 litres for the 
sake of further investigation. 
2. Carbonic acid.—A litre of this liquid gave with nitrate of silver a pre- 
cipitate of carbonate and sulphide of silver. Treated with ammonia, the car- 
bonate dissolved, and was separated from sulphide by a weighed filter, and pre- 
cipitated in the filtrate as chloride of silver by means of hydrochloric acid. Its 
weight amounted to 3.0475 grammes, which corresponds to 0.4687 grammes 
combined carbonic acid; hence in the entire residue there were 2.8126 grammes 
combined carbonic acid. 
As a control, the carbonic acid was determined by chloride of manganese by 
mixing a litre of the liquid with a solution of this salt which had been previously 
fused; a precipitate of carbonate of manganese was obtained, the carbonic acid 
of which, determined in the usual manner, corresponded to 2.8337 grammes 
in the entire residue. 
3. Hyposulphite of potash.—The sulphide of silver (2) weighed on the tared 
filter, when dried at 120°, 0.2261 grammes, which corresponds to 0.1733 
grammes hy posulphite of potash; hence the entire residue contained 1.0400 
grammes hyposulphite of potash. 
A determination of the hyposulphite was also made by metrical analy- 
sis. A litre of the solution was acidulated with acetic acid, mixed with 
starch, and determined by means of a standard solution of iodine. A litre 
pp anal cubic centimetres iodine solution ; hence, according to the formula 
——— =, in which ¢=22.57, a= 0.000517; this litre contained 
0.1746 grammes hyposulphite of potash, and the entire residue 1.0476 grammes 
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 @==0.04853, the quantity of hydrochlorie acid taken; 
t— 19.87, the number of divisions of an ammoniacal liquid which would poms 
saturated a volume of hydrochloric acid equal to that taken with ¢/= 41.30 
divisions of the burette. Using the formula z= ae eS : aft—t) , I found 
in the 4 litre the sesquicarbonate of ammonia to be 0.041275 iiteey hence 
0.9908 gramme corresponds to the entire quantity of sesquicarbonate of Saone 
Br Carbonate of potash.—Subtracting the carbonic acid in the sesquicarbon- 
ate of ammonia 0.5541 gramme from the total quantity found (2),— 2.8337 
grammes, there remains a quantity corresponding to the carbonate of potash 
==2.2796 grammes. Hence the entire residue contains 7.1498 grammes car- 
bonate of potash. 
6. Sulphate of potash.—A litre of the liquid mixed with chloride of barium 
gave 3.0244 grammes sulphate of baryta, which corresponds to 2.2683 grammes 
\ ae of potash for one litre of liquid, and 13.6100 grammes 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 sul- 
phurie acid and ignited in a platinum vessel, 3.8466 grammes of sulphate of 
