INSECT POWDER. 
43 
resemble that of chamomile. This method is somewhat different 
from that given by them in 1898 (42), a slight modification of Dur- 
r ant's test in which the extraction of the sample with ether was 
continued as long as the solvent took up anything, instead of ex- 
hausting with a specified quantity of ether. This method differs 
from that published by Fromme in 1900 only in the time of macera- 
tion, being two hours instead of one. 
Caesar and Loretz (42) found that insect powder made from closed 
flowers yielded from 8 to 9.5 per cent of extract, while open or partly 
open flowers gave 6.5 to 7.5 per cent. They state that the color of 
the extractions varies from pure yellow, dark yellow, and brownish 
yellow to greenish yellow, while that prepared from stems is of a 
dirty-green color, and the residue amounts to only 5.5 per cent. 
They state furthermore that the insecticidal properties of insect 
powder are fully represented in the ether extract, and are not due 
to any alkaloidal bodies that the powder may contain. 
Linke (173) obtained the values shown in Table 20 on six authentic 
powders. 
Table 20. — Chemical analysis of authentic insect poivders and whole flowers {Linke). 
Determination. 
Sample No. 
Moisture 
(loss at 
100-105°). 
Ether 
extract 
(Durrant's 
method). 
Ash. 
Powder: 
1 
Per cent. 
9.08 
9.64 
7.20 
6.66 
6.22 
5.24 
10.72 
10.36 
10.76 
Per cent. 
4.28 
5.48 
15.56 
5.22 
6.26 
5.56 
Per cent. 
7.04 
2 
7.52 
3 
7.64 
4 
5 
6 
6.56 
"Whole flowers: 
1 
5.88 
2 
6.44 
3 
6.44 
i 6. 80 per cent when shaken continuously for 2 hours. 
In the ash, the presence of iron, manganese, aluminum, calcium, 
magnesium, sodium, and potassium was shown, but in no instance 
was chromium found. After evaporating the ethereal solution the 
residue was dried at 100° C. for one hour before weighing. 
Sattler (238) reports finding lead chromate in an insect powder, 
the ash of which was 6.105 per cent. Wiebelitz (293), 1912, found 
a lower ash content in two samples of insect powder than that usually 
reported, namely, 4.7 per cent and 5.1 per cent. Siedler (150), in 
1912, obtained the results given in Table 21 on pure insect powder 
and on stem powder. 
