ARSENICALS. 
17 
centages of the total lead present in the sample: For the one-hour 
period, 3 per cent; for the one-day period, 7 per cent; and for the 
three-day period, 7.6 per cent. The results for water-soluble ar- 
senic in the combinations are lower than those for water-soluble ar- 
senic in the arsenicals alone. It is evident that the excess lime of the 
Bordeaux combined with part of the soluble arsenic present in the 
arsenates, forming insoluble calcium arsenate. 
The results show that Bordeaux mixture and the arsenates of lead 
and calcium, as well as Paris green, are compatible, that a soluble ar- 
senate, such as sodium arsenate, may be used in quantities large 
enough to act as an insecticide in combination with ordinary Bordeaux 
mixture, and that the excess lime of the Bordeaux will combine with 
the soluble arsenic to form insoluble calcium arsenate. 
ARSENATES AND KEROSENE EMULSION. 
As kerosene emulsion is occasionally used in combination with acid 
lead arsenate and may be used with calcium arsenate, a series of 
experiments was undertaken to determine whether detectable chemical 
changes take place in these combinations. 
A kerosene emulsion was prepared according to the following direc- 
tions : 6 One liter of commercial kerosene oil and 1 ounce of sodium 
fish-oil soap in water were mixed, and the resulting emulsion was 
diluted to 10 liters. 
A series of 300 cubic centimeter flasks were rilled with this emulsion 
and 0.8 gram of acid lead arsenate (sample 39) or 0.667 gram of cal- 
cium arsenate (sample 57) was added to each of the flasks, with the 
exception of the control flasks. Mixtures of the arsenates alone 
and of the emulsions alone were used for controls. The mixtures 
were agitated at 35° C. for periods of one hour, one day, and three 
days. They were filtered immediately and the filtrates were tested 
for arsenic. The average figures only are recorded in Table 7. 
Table 7. — Soluble arsenic in filtrates from combinations of arsenicals ivith Bordeaux 
mixture and with kerosene emulsion. 
Sample 
No. 
Material analyzed. 
Total ar- 
senic (As) 
in sample 
taken. 
Soluble arsenic (As) found 
after standing for— 
Percentage of total ar- 
senic (As) found soluble 
after standing for — 
1 hour. 
lday. 
3 days. 
1 hour. 
lday. 
3 days. 
25 
Grams. 
0. 1709 
. 1938 
.1753 
.1709 
Grams. 
Grams. 
Grams. 
0. 1650 
.0066 
.00034 
.0048 
.00006 
.00001 
.00046 
.00000 
.00018 
.0122 
.0740 
Per cent. 
Per cent. 
Per cent. 
96 55 
64 
Paris green 
3.41 
57 
Calcium arsenate 
0.20 
39 
Acid lead arsenate 
2.81 
61 
Bordeaux mixture 
Sodium arsenate (25) plus 
Bordeaux (61) 
.1709 
.1938 
.1753 
.1709 
.1753 
.1709 
0.00095 
00113 
.00003 
.00051 
.OOLS 
.0332 
0.00001 
.00053 
.00005 
.00030 
.0095 
.0768 
0.56 
.58 
.02 
.30 
1.03 
19.43 
0.00 
.27 
.03 
.18 
5.42 
44.94 
.00 
— 
Paris green (64) plus Bor- 
deaux (61) 
.24 
— 
Calcium arsenate (57) plus 
Bordeaux (61) 
.00 
— 
Acid lead arsenate (39) plus 
Bordeaux 
.11 
— 
Calcium arsenate (57) plus 
kerosene emulsion 
Acid lead arsenate (39) plus 
kerosene emulsion 
6.96 
43. 30 
e Taken from U. S. Dept. Agr. Farmers' Bull. 958, p. 28. 
27476°— 23— Bull. 1147 3 
