INSECT POWDER. 



33 



method for the detection of added coloring matter as more accurate 

 than the microscopic method. The results obtained on these 12 

 samples are shown in Table 5. 



Table 5. — Chemical examination of insect powder (Hoivie). 



Sample 



No. 



Vendor's dofliiition. 



Color. 



Adulterant. 



Ash. 



1 



Insect powder 



Drab 



Genuine 



Percent. 

 6 2 



2 



do 



do 



do 



7 1 



3 





Olive drab 



.... do 



6 



4 





Yellowish 



do 



6 8 



5 



All closed flowers 



do 



do 



6.2 



6 



Open flowers 



.... do 



.... do 



6 2 



7 





Yellow 



Chrome 



10. .5 



8 



do 



do 



do 



9.6 



9 



Opt 



do 



do 



9.2 



10 



All closed flowers 



do 





8.0 



11 



Foreign 



do. 



Chrome . 



9.4 



12 





Very yellow 





6.0 











An anonymous writer in 1884 (13) suggested testing insect powder 

 with ammonia water, which would cause an artificially colored powder 

 to turn a more or less dark brown, while an uncolored powder would 

 change only slightly. Exposed to direct sunlight a genuine powder 

 in the course of a few hours loses its color, according to this writer. 

 Meyer (202), in 1887, proposed to test for mineral impurities in an 

 insect powder by shaking the sample with chloroform, which would 

 cause the powder to rise to the top of the liquid, while the inorganic 

 substances would settle to the bottom. 



In 1888 Hart (119) found an ash content of from 6.10 to 6.40 per 

 cent in samples of insect powder and one of from 5.40 to 6.10 per cent 

 in insect flowers. The ash content of the peduncles and receptacles 

 of the flowers was 5.60 per cent. Beringer (29), in 1889, made the 

 determinations given in Table 6 on flowers of the Chrysanthemum 

 dnerarisefolium and of the Hungarian daisy (C. leucanthemum) . 



Table 6. — Chemical analysis of flowers of C. cinerariaefolium and C. leucanthemum 



{Beringer). 



Product. 



Determination. 



T'otro- 



leum- 



ether 



extract. 



Ether 

 extract. 



Alcohol 

 extract. 



Water 

 extract. 



Chrysanthemum cinerarixfolium. 

 Hungarian daisy 



Per cent. 

 2.49 

 3.37 



Per cent. 

 2.85 

 2.68 



Per cent. 

 6.57 

 9.45 



Per cent. 

 16.70 

 13.43 



Per cent. 

 6.50 

 9.30 



Beringer stated that no difference could be detected between the 

 two powders by microscopical examination. 

 139815°— 20— Bull. 824 -3 



