INSECT POWDER. 
39 
results with the physiological test because of the difference in size, 
health, etc., of the insects. In good samples of insect powder the 
ether extract varies between 5 and 9 per cent." 
Dietze (70), of the firm of J. D. Kiedel, Berlin, records numerous 
tests on insect powders (Table 15). He used powder ground by 
himself from closed flowers, and also commercial powders. Dietze 
prefers petroleum ether to ordinary ether as a solvent, as the former 
takes out the " active principle only," whereas ordinary ether extracts 
a number of other substances at the same time. In most cases the 
ether extract is more or less green, and has a less powerful odor than 
the petroleum-ether extract. Table 16 shows the results obtained 
upon various adulterants of insect powder. 
Table 15. — Chemical analysis of insect powder {Dietze). 
Determination. 
Moisture 
(loss at 
100°). 
Ash. 
On water-free basis. 
Sample No. 
Soluble in— 
Ether. 
Ordinary 
petro- 
leum 
ether. 
Purest 
petro- 
leum 
ether. 
Chloro- 
form. 
Equal 
mixture 
Specific 
gravity, 
0.735. 
Specific 
gravity, 
0.720. 
of chloro- 
form and 
ether 
(0.720). 
Powders prepared 
from closed flowers: 
1 
Per cent. 
7.43 
3.42 
5.51 
8.10 
6.16 
7.41 
6.95 
4.55 
8.90 
7.23 
9.85 
8.48 
8.06 
Per cent. 
7.68 
8.26 
8.28 
7.37 
8.34 
6.70 
7.70 
7.77 
6.65 
6.75 
7.08 
7.67 
7.49 
Per cent. 
9.38 
8.59 
7.27 
8.14 
8.23 
6.44 
6.46 
6.78 
6.78 
6.71 
7.41 
6.59 
6.12 
Percent. 
7.41 
Per cent. 
Per cent. 
Per cent. 
7.02 
Per cent. 
6.81 
2... 
3... 
4 
5 
7.74 
4.35 
5.24 
5.01 
5.78 
5.01 
4.88 
4.49 
5.92 
3.68 
2.61 
3.12 
2.09 
3.35 
2.83 
2.02 
2.46 
2.97 
6 
2.50 
3.15 
2.93 
7 
8.. 
9 
10 
5.26 
5.17 
11 
2.76 
2.60 
3.03 
12 
13 
Minimum 
Maximum 
Average 
Commercial powders: 
1 
3.42 
9.85 
7.08 
8.33 
7.76 
9.15 
7.03 
7.63 
7.88 
11.79 
8.68 
9.20 
6.70 
8.62 
4.55 
6.65 
8.34 
7.52 
6.85 
6.58 
9.08 
8.37 
8.14 
6.83 
6.63 
7.36 
6.94 
8.10 
7.45 
10.89 
6.12 
9.38 
7.30 
4.34 
4.66 
7.28 
5.19 
6.09 
6.87 
6.03 
8.68 
8.51 
6.18 
4.41 
3.72 
4.35 
7.74 
5.61 
2.98 
3.15 
5.12 
4.97 
4.52 
4.04 
4.29 
5.17 
6.17 
3.52 
2.41 
3.43 
2.50 
3.15 
2.99 
2.52 
3.68 
2.86 
1.53 
5.26 
7.02 
6.14 
5.17 
6.81 
5.99 
2 
3 
2.64 
2.29 
2.64 
2.91 
2.38 
3.29 
2.81 
4 
2.48 
2.83 
5 
6 
3.03 
2.48 
3.47 
3.09 
2.07 
1.60 
2.79 
4.87 
5.19 
8 
6.03 
5.86 
9 
10 
11 
12 
Minimum 
Maximum 
Average 
4.55 
11.79 
8.11 
6.63 
10.89 
7.77 
3.72 
8.68 
5. 99 
2.41 
6.17 
4.15 
1.60 
3.47 
2.63 
1.53 
3.29 
2.56 
4.87 
6.03 
5.43 
2.83 
5.86 
4.63 
