40 BULLETIN 824, U. S. DEPARTMENT OF AGRICULTUEE. 



Table 16. — Chemical analysis of insect powder adulterants (Dietze). 



Adulterant. 



Determination. 



Moisture 

 (loss at 

 100°). 



Ash. 



Soluble in- 



Ether. 







Ordinary 







petro- 

 leum 



Specific 



Specific 



gravity, 



gravity, 



ether. 



0.735. 



0.720. 





Per cent. 



Per cent. 



Per cent. 



3.76 



3.17 



2.46 



7.51 



4.96 



4.69 



10.06 



5.34 



4.09 



8.20 



7.59 



4.25 



0.23 



0.21 



0.18 



5.91 



3.69 



3.36 



Purest 

 petro- 

 leum 

 ether. 



Johannesblumen von Chrys. Leucanthe- 



mum 



rior. chamom. vgl 



Flor. chamom. Roman 



Flor. chamom. Calendulas 



Lignum quassise 



Folia sennse 



Per cent. 



7.59 

 10.39 



6.78 

 11.85 



0.99 

 10.13 



Per cent. 

 8.22 



12.72 

 8.65 

 9.19 

 2.66 



11.06 



Per cent. 

 2.25 

 4.14 

 4.05 

 4.32 

 0.10 

 3.39 



Dietze declares that the value of an insect powder can not be 

 determined by any of these extraction methods, whether made 

 with ether, petroleum ether, or chloroform, and the determination of 

 ash and moisture, but that a practical test upon insects is necessary. 



Fromme (85), in 1900, pubhshed results for ether extract deter- 

 minations of from 6 to 7 per cent on half -opened buds and from 7 

 to 9.5 per cent on unexpanded buds. The ether extract of pure 

 flowers is of a golden-yellow color, while that of the stalks is of a 

 greenish tint, thus making it easy to detect such adulteration. 



Haywood (121) gives the results of the chemical examination of a 

 number of commercial insect powders shown in Table 17. 



Table 17. — Chemical analysis of commercial insect powders (Haywood). 





Determination. 



Product. 



Mois- 

 ture. 



Ash. 



Ether 

 extract. 



Lead 

 in ash. 



Chro- 

 mium 

 in ash. 



Barium 

 in ash. 



Turmeric, 



Black flag insect powder 



■Rnhach 



Per cent. 

 7.21 

 6.96 

 5.82 

 7.39 

 6.75 

 7.49 

 6.24 

 7.68 

 6.47 

 6.87 



Per cent. 

 8.01 

 9.69 



12.02 

 7.80 

 7.74 



11.91 

 8.35 

 6.47 

 5.90 

 8.03 



Per cent. 

 8.91 

 9.09 

 5.15 

 8.38 

 10.68 

 6.68 

 6.43 

 6.22 

 6.35 

 6.78 



None.... 

 ...do.... 



Present . 



None 



...do.... 

 ...do.... 

 ...do.... 

 ...do.... 

 ...do.... 

 ...do.... 



None 



...do.... 



Present . 



None 



...do..- 

 ...do.--- 



...do 



...do.-.. 

 ...do.-. 

 ...do 



None 



...do.... 

 ...do.... 

 ...do.... 

 ...do.... 

 ...do.... 

 --do.... 

 --do.... 

 --do.... 

 ...do.... 



None. 

 Do. 



Persian insect powder 



Do. 



PjTethrum insect powder 



Death dust for insects . . 



Do. 

 Do. 



Pyrethrum powder 



Do. 



Dalmatian insect powder 



Tiger insect powder 



Do. 

 Do. 



Magic insect powder 



Do. 



Insect powder 



Do. 







Later, Haywood (122) gives the results of the examination of 

 commercial insect powders for the presence of chromates. Chro- 

 mium was determined quantitatively in the ash by titration with 

 permangknate, and the values calculated to lead chromate. Of 105 

 samples examined, 19, or 18 per cent, were colored with lead chro- 

 mate, the amount of which varied from 0.12 to 1.47 per cent. 



