102 
HYDROCYANIC-ACID GAS FUMIGATION IN CALIFORNIA. 
manipulation. The average amount decomposed is less than 2 per 
cent and the average remaining in the residue is practically 3 per cent, 
which shows that when operating with pure sodium cyanid and sul- 
phuric acid we may expect to obtain close to 95 per cent of the theo- 
retical yield of hydrocyanic-acid gas expelled and available for 
fumigation purposes. Sodium cyanids were then prepared containing 
varying quantities of sodium chlorid and the determinations made in) 
the same way. The results are tabulated as follows: 
Equiva- 
lent of 
HCN in 
sample. 
Sodium 
chlorid 
in sam- 
ple. 
HCN 
evolved. 
HCN re- 
maining 
in resi- 
due. 
HCN de- 
com- 
Per cent of total HCN. 
Experiment No.— 
posed 
(by differ- 
ence.) 
Evolved. 
In res- 
idue. 
Decom- 
posed. 
6 
Per cent. 
47.16 
43.18 
34.55 
25.91 
17.27 
Per cent. 
9 
16f 
33j 
50 
66s 
Per cent. 
41.96 
27.42 
10.57 
5.85 
1.27 
Per cent. 
0.66 
1.71 
.37 
.05 
.10 
Per cent. 
4.54 
14.05 
23.61 
25.91 
15.90 
88.98 
63.49 
30.61 
22.58 
7.35 
1.40 
3.97 
1.06 
.21 
.63 
9.62 
7 
32.54 
8 
68 33 
9 
77.21 
10 
92.09 
AMMONIA FORMED FROM THE DECOMPOSITION OF THE CYANID. 
The amount of ammonia, existing as ammonium sulphate, in the 
residue in flask "A" and that passed over into "B" was determined 
in several cases and the nitrogen calculated therefrom. These 
amounts added to the calculated amount of nitrogen in the hydro- 
cyanic acid recovered in "A" and "B" correspond almost exactly 
with the theoretical amount of nitrogen in the quantity of cyanid 
employed . The distribution of nitrogen was as follows : 
Distribution of nitrogen in the residue. 
Determination. 
Experi- 
ment 7. 
Experi- 
ment 8. 
Experi- 
ment 9. 
In "A": 
Nitrogen as cyanid . . 
Nitrogen as ammonia 
In"B": 
Nitrogen as cyanid . . . 
Nitrogen as ammonia 
Per cent. 
49^84 
46.83 
2.54 
Per cent. 
1.05 
66.82 
30.40 
1.73 
Per cent. 
0.21 
73.11 
23.23 
3.45 
This shows that one of the principal decomposition products is 
ammonia, the greater part of which is held in solution in the generating 
flask by the excess of sulphuric acid as ammonium sulphate. 
Experiments carried out on the samples of commercial cyanids, 
the analyses of which are given on page 92, gave the following results: 
