INSECT POWDER. 



37 



mercial insect 

 to 13.95 per 

 Annalen, 1886- 

 made on insoc 

 as the limiting 

 cent; ash, 6.07 

 to 38.33 per 

 microns. 



powder: Maxhnum size, 255 microns; moisture, 5.55 

 cent. In the Erstes Dezennium der Helfenberger 

 -95 (page 420), as the average of all determinations 

 t powders during that period, the following are given 

 values: Moisture (loss at 100°), 5.55 to 13.95 per 

 to 8.70 per cent; potassium carbonate in ash, 28 

 cent; maximum size of particles, 109.44 to 175.50 



Tat?le 13. — Chemical analysis of insect powders (Dieterich). 





Year. 



Determination. 



Maximum 



size of 

 particles. 



Sample No. 



Moisture 

 (loss at 

 100°). 



Ash. 



K2C03in 



ash. 



1 



1896 

 i 1897 



1900 



[ 1901 



i 1902 



I 1903 

 1904 



Per cent. 

 ( 9.55 

 { 8.25 

 I 11. 18 



f 12. 12 

 1 9.53 

 1 11.12 

 I 10.60 



f 11. 26 

 6.95 



Per cent. 

 8.35 

 7.65 

 7.58 



7.38 

 6.61 

 7.45 

 6.80 



8.06 

 6.40 

 7.13 

 7.56 

 8.75 

 6.38 

 6.90 



6.65 

 7.63 

 9.94 

 9.63 



7.01 

 6.39 

 6.16 



7.40 

 6.75 

 7.30 



6.35 



Per cent. 

 23.47 

 31.57 

 30.96 



33.80 

 38.05 

 17.01 

 33.51 



Microns. 

 179.55 



2 



255. 15 



3 . 



151. 20 



1 



190.35 



2 



139. 05 



3 



153.90 



4.. 



141. 75 



1 



148. 50 



2 . 





311.85 







302.40 



4 . 



9.93 

 9.33 





141, 75 







155.25 



(i 





155. 25 





[ 7.43 



f 10. 33 

 1 11.97 

 1 9.28 





198. 45 



1 





198. 45 



2. . ... 





145.50 



3;;:: :::::::::::::;::::::::::::: :::::::::: 







4. . 







1 



1 7.97 

 { 8. .S3 

 I 10.52 



( 10. 04 

 \ 8.57 

 I 9.05 



8.81 





202.50 



2. . ... 





135.00 



3 





67.50 



1 





190.35 



2 





162. 00 



3 





135.00 



1.. 





162. 00 









In the Helfenberger Annalen for 1902 (page 186), Dieterich reports 

 the results of the determination of the ether extract of insect powders, 

 using the method of Fromme (85), in which 8 grams of powder are 

 treated with 80 grams of ether of specific gravity 0.720 at 15° C, 

 shaken at intervals during 1 hour, then 50 grams (=5 grams powder) 

 shaken with 1 gram of water, filtered, the filter thoroughly washed 

 with ether, and the filtrate evaporated and weighed. The extract 

 of insect powders made in this way varied from 5.16 to 5.38 per cent, 



Durrant (73) is the author of the ether extraction method that 

 has been most generally applied in the valuation of insect powder. 

 He proceeds as follows: 



Place 100 grains of the powder in the cylinder of a glass syringe (1 ounce). The 

 powder should be pressed down compactly on to a piece of absorbent cotton to act 



