AESENICALS. 
19 
lime soaps, for which reason more arsenic was left in a free or soluble 
form when acid lead arsenate was used than when calcium arsenate 
was used. Based on the results of chemical analyses, both of these 
mixtures are incompatible. 
ACID LEAD OR CALCIUM ARSENATES AND NICOTINE SULPHATE SOLUTIONS. 
Mixtures of acid lead arsenate and of calcium arsenate with a 
solution of nicotine sulphate were prepared and analyzed. A 1-800 
dilution of a 40 per cent solution of nicotine sulphate was made. In 
the first series 500 cubic centimeter flasks were filled with this dilute 
nicotine sulphate solution and 1.2 grams of acid lead arsenate (sample 
39) or 1 gram of calcium arsenate (sample 57), containing 13 per cent 
of free calcium oxid was added to each of the flasks, with the ex- 
ception of the controls. Results of the analyses of the lead and cal- 
cium arsenates used are given in Table 3. After agitating the differ- 
ent solutions for periods of one hour, one day, and three days they 
were immediately filtered and the filtrates were analyzed for arsenic 
and nicotine. Nicotine was determined by the official silicotungstic 
acid method (1). A second series of tests, using two commercial 
calcium arsenate samples (Nos. 32 and 59) and a pure tricalcium 
arsenate prepared by C. M. Smith, was made. Sample 32 contained 
9.99 per cent, sample 59, 5.23 per cent, and sample 464 no free calcium 
oxid. In this series 0.6 gram of the calcium arsenate was placed in 
each of a series of 300 cubic centimeter flasks, which were made to 
volume with the dilute nicotine sulphate solution. These solutions 
were agitated for one hour and for three days. 
Table 9. — Results of combining acid lead arsenate or calcium arsenate with nicotine- 
sulphate solutions. 
Material analyzed. 
Soluble nicotine after agi- 
tating for — 
1 hour. 1 day 
days. 
Soluble arsenic oxid (As 2 5 ) 
after agitating for— 
1 hour. 1 day. 3 days. 
500 
30(i 
cubic centimeter volume tests: 
Nicotine-sulphate solution 
Acid lead arsenate (39) plus nicotine 
sulphate 
Calcium arsenate (57) plus nicotine 
sulphate 
Acidlead arsenate (39) 
Calcium arsenate (57) 
cubic centimeter volume tests: 
Nicotine-sulphate solution 
Calcium arsenate (32) plus nicotine 
sulphate 
Calcium arsenate (59) plus nicotine 
sulphate 
Calcium arsenate (464) plus nicotine 
sulphate 
Calcium arsenate (32) 
Calcium arsenate (59) 
Calcium arsenate (464) 
Grams. 
0. 2748 
.2748 
.2778 
.0000 
.0000 
.1740 
.1750 
.1760 
.1740 
Grams. 
0.2780 
.2815 
.0000 
.0000 
Grams. 
0.2820 
.2763 
.2815 
.0000 
.0000 
Per cent. 
0.00 
.45 
.44 
.60 
.30 
.00 
1.15 
11.04 
10.39 
.27 
2.09 
3.34 
Per cent. 
Per 
0.34 
.52 
cent. 
0.00 
.60 
.50 
.00 
1.09 
11.50 
11.86 
.27 
2.22 
3.57 
The results (Table 9) show that acid lead arsenate (sample 39) 
when combined with nicotine sulphate gives no increase of soluble 
arsenic and that the amount of soluble nicotine is not altered. This 
mixture is therefore chemically compatible. 
