36 BULLETIN 824, U. S. DEPARTMENT OF AGRICULTURE 
dirty-green color, and, the residue amounts to only 5.5 per cent. 
They state furthermore that the insecticidal properties of insect 
powder are fully represented in the ether extract,and are not due 
to any alkaloidal bodies that the powder may contain. 
Linke (173 obtained the values shown in Table 20 on six authentic 
powders. 
TaBLE 20.—Chemical analysis of authentic insect powders and whole flowers (Linke) 
Determination 
Sample No. NAGISHHES ee 
(loss at (Durrant’s | Ash 
INE) method) 
Powder: Per cent Per cent Per cent 
2 ps Dor eet ean aw Naa Me RESIGN aie tintin Dis St sot yd wll ately See ae gs te 9. 08 4, 28 7. 04 
DeoWes A EEE Phd Oh pore Pi CG SR Ee Ee 9. 64 5. 48 7. 52 
Ee 5 UR ae ei, eee ee eles meh cree aed Sey ee ee le oe ee 7. 20 15. 56 7. 64 
Qs hikers wi Fete EEA CELE ERA itn oh In Re ae 6. 66 O22 || RL eee 
Go ieeu Pup sera page cy! aes Tip ee re FA epi ae: Teh oe gee. Silly Be 6. 22 6226) 
Re aR A ene eH ME ee SE i ren Se RI Fe als a) oo EA Mb RE 5. 24 5. 56 6. 56 
Whole flowers: 
LR RO aa ee eee NU, Seb Seer See mt re Na eee eee ere Se A LOE G2) | ee eee 5.88 
DENT Pipe SRO NR Se ee RNS ee eb ae ee Re es ee a 1LOS36-|222 Seas 6. 44 
Qe Seis ricce 0). ia bee pee! Ie) fh Pa Ree ee ee EE 10! 26\\|-22 a es 6. 44 
16.80 per cent when shaken continuously for 2 hours. 
In the ash, the presence of iron, manganese, aluminum, calcium, 
magnesium, sodium, and potassium was shown, but in no instance 
was chromium found. After evaporating the ethereal solution the 
residue was dried at 100° C. for one hour before weighing. 
Sattler (238) reports finding lead chromate in an insect powder, 
the ash of which was 6.105 per cent. Wiebelitz (293), in 1912, found 
a lower ash content in two samples of insect powder than that usually 
reported, namely, 4.7 per cent and 5.1 per cent. Siedler (150), in 
1912, obtained the results given in Table 21 on pure insect powder 
and on stem powder. 
TABLE 21.—Chemical analysis of pure insect powder and stem powder (Siedler) 
Determination 
Product : 
Moisture ae Ether 
at 110° ie extract 
rial 
Per cent Per cent Per cent 
iPure:insect powder0- |. ase So Pee eae ie ee eae ee a ee ee 10:77" |> 6:8E.107 294 eee 
Row der from: Dest Ho werss Soe Bee oe Se hl ra ee ee asi fa oa 6. 14 
SSE CIITA OW, CLO ee cee ae ee nh En ee Ae te OO 8. 69 6. 39 1.48 
Wnpowdereds butiftinely-cuG Howersst5- = oe ee ek eee Gi S6s/Eoe antec 
Siedler used ether with a specific gravity of 0.720, and, after com- 
pletely extracting the sample in the cold, allowed the ether to ae 
orate spontaneously, and dried the residue for one hour upon t 
water bath. The color of the extract of the powdered flowers was 
dirty yellow, that of the stem powder green. With concentrated 
sulphuric acid there was no characteristic color reaction with either 
resinous residue. Siedler found the petroleum-ether extract of pure 
