INSECT POWDER. 
35 
In another place (282, p. 167) Unger has recorded the results 
shown in Table 10. 
Table 10. — Chemical analysis of insect powders and flowers from Dalmatia ( Unger). 
Product. 
Determination. 
Sam nl e 
No. 
Moisture. 
Ash on 
water- 
free 
basis. 
Remarks. 
1 
Per cent. 
8.56 
Per cent. 
8.33 
No manganese; barium chromate and stems 
present. 
Do. 
2 
.. .do 
3 
. .do 
7.3 
6.74 
No manganese; much iron. 
Strong in manganese. 
4 
Flowers from Spalato 
8.44 
From the fact that he found no manganese in Pyrethrum stems, 
while it was always present in the flowers, Unger proposed to deter- 
mine whether a powder was strongly adulterated with stems by test- 
ing for manganese. Thorns (274), in 1890, however, found manganese 
in the ash of 0. leucanihemum and P. indicum, and Siedler (258) 
showed that Pyrethrum stems are not entirely manganese-free. 
Appreciable quantities of manganese in Pyrethrum stems from 
Japan have been found by the authors. 1 Unger's test is of no value. 
Thorns (274), in 1890, reported an ash content of 6.93 per cent in 
whole flowers of C. cinerarisefolium, and one of 6.94 per cent in the 
same after powdering. He (275) would determine the value of an 
insect powder by a determination of its ash and petroleum-ether ex- 
tract, together with a microscopical examination. From Dalmatian 
insect powder which had been dried at 100°, Thorns obtained by ex- 
tracting with petroleum ether 5.34 per cent of a brown-yellow extract 
(dried at 80°), which had a strong odor of insect powder. Other 
powders gave from 5 to 3.89 per cent. An adulterated insect pow- 
der gave only 3.83 per cent extract, without the characteristic odor. 
Flowers of Chrysanthemum leucanihemum (Hungarian daisy) yielded 
4.02 per cent extract. 
The Chemist and Druggist for March 22, 1890 (17), reports an ash 
content of 6 per cent on a sample of insect powder prepared from 
flowers grown in Gippsland, the southeastern district of Victoria, 
Australia. 
Eymard (77), 1890, gives the analysis of Pyrethrum powder 
shown in Table 11. 
1 Manganese was determined in the various grades of insect flowers and stems of both Dalmatian and 
Japanese origin, the following average amounts being found: Japanese stems, 0.0123 per cent; Dalmatian 
stems, 0.0077 per cent; Japanese closed flowers, 0.0155 per cent; Dalmatian closed flowers, 0.0096 percent; 
Dalmatian open flowers, 0.0076 per cent. The manganese content of both stems and flowers varies so 
greatly and differs so little in the two parts of the plant that any method for estimating the amount of 
powdered stems in an insect powder from a determination of its manganese content is valueless. 
