62 BULLETIN 824, U. S. DEPARTMENT OF AGRICULTURE. 



Table 39. — Analysis of adulterated commercial insect powders — Continued. 



Sam- 

 ple 

 No. 



Made in- 



Nitro- 

 gen, N. 



Ash. 



Ash in- 

 soluble 



in 

 HCl. 



Color of ether extract. 



Adulterants. 



17384 

 17420 



United States . . 

 do.. 



Per ct. 

 0.954 



.856 

 .947 

 .849 

 .807 

 1. 030 

 1.185 

 .887 

 1.060 

 .954 

 .772 

 1.145 

 1. 015 

 .786 

 1.040 

 1.165 

 1.090 

 1.050 

 1.120 

 .898 

 1.170 



Per ct. 

 7.14 

 5.70 

 5.66 

 7.62 

 6.36 

 6.69 

 7.18 

 6.06 

 7.19 

 6.16 

 4.96 

 10.12 

 6.09 

 5.27 

 6.57 

 6.75 

 7.05 

 8.68 

 7.00 

 6.38 

 6.10 



Per ct. 



0.85 

 .90 

 .56 



1.14 

 .61 



1.42 



1.13 

 .37 

 .74 

 .61 

 .59 



4.31 

 .40 

 .66 

 .80 

 .83 

 .70 



3.18 

 .76 

 .69 

 .82 



Green 



do 



All stems. 



17998 

 18153 

 19145 



do.... 



do.... 



do 





do 



do 



Strong green 



Stems. ^^^^^^B 

 All stems. ' ^^^^^Ft 

 Stems. 



19846 

 20765 



do 



do 





do 



Greenish yellow 



Strong green 



Do. 

 Do. 



20786 



do.... 



.do 





Do. 



20787 





Do. 



20793 



do 





do 



Strong green 



Do. 



20940 



do. . 





Do. 



21115 

 22215 



do 



do.... 



do 





Greenish yellow 



Stems and sand. 



Potassium chromate and stems. 



23161 



Strong green 



All stems. 



23369 



.do 









23479 

 23547 

 24030 

 24768 

 247fi9 



do.... 



do.... 



do.... 



do 



do 





do 



do 



do 



do 



Do. 

 Do. 



Stems and sand. 

 Stems. 

 Do. 



25046 



.. ..do 





Green . . 



Do. 











Table 40. 



-Analysis of commercial powders containing stems, amounts declared, made 

 from "open" flowers and stems. 



Sample No. 



Nitrogen, 



N. 



PaOj. 



Stems 



stated 



to be 



present. 



Stems calculated 

 from — 



Mean. 



Error. 



Nitrogen, 



N.' 



PjOs. 



12031 



Per cent. 



0.891 



1.080 



1.135 



.950 



.947 



1. 030 



.887 



1.060 



.9.54 



.786 



1.040 



1.090 



1.050 



Per cent. 



0.289 



.402 



.385 



.'284' 



Per cent. 

 75 

 50 

 50 

 50 

 75 

 50 

 70 

 40 

 50 

 100 

 50 

 50 

 50 



Per cent. 

 75 

 37 

 26 

 63 

 64 

 47 

 76 

 41 

 62 

 96 

 45 

 35 

 43 



Per cent. 

 81 

 43 

 49 



Per cent. 

 78 

 40 

 38 



Per cent. 



+ 3 

 — 10 



12073 : 



12658 



— 12 



14039 



+ 13 

 _ 1 



14362 



83 



74 



19846 



— 3 



20786 



.316 

 .390 



72 

 47 



74 

 44 

 62 



+ 4 

 + 4 

 ■h 12 



_ 4 



20787 



20793 



23161 







23369 









— 5 



23547 









— 15 



24030 









_ 7 













Minimum error 















1 



Maximum error 















15 



Average error 















7 



















From Table 40 it is evident that the amount of stems in commercial 

 insect powder determined by the proposed method of calculation from 

 the values for nitrogen and phosphorus pentoxid agrees within an 

 average of less than 10 per cent of the amount declared to be present. 



In some cases the ash and acid-insoluble ash contents in insect 

 powders have been found to be higher than they should be, based on 

 those determinations made on samples of known purity and on 

 samples of flowers and stems. Some jobbers have claimed that the 

 high ash content of their product was due to the addition by the 

 manufacturer of siliceous material during the grinding or to the intro- 



