INSECT POWDER. 69 
yellow crystals and had a melting point of 70 ° to 1 00 ° . After repeated 
recrystallization from cold ether a paraffin, C 17 H 36 , of melting point 
64°, was obtained. This dissolved freely in ether, benzene, chloro- 
form, and moderately hot alcohol, but was almost insoluble in cold 
alcohol. The portion remaining in cold ether was recrystallized 
until the melting point was above 150°. Pure cholesterin was pre- 
pared from either the acetyl or benzoyl derivative of this substance 
by the action of alcoholic potash. The cholesterin thus obtained had 
a melting point of 183°; the melting point of its acetyl derivative 
was 223°, and that of the benzoyl derivative, 246°. It dissolved 
freely in ether, benzene, and chloroform, sparingly in hot alcohol, 
and gave all the reactions for cholesterin. 
In 1890, Zuco (297, 298) obtained a glucoside and also an alkaloid 
from the flowers of Chrysanthemum cinerarixfolium. He described 
the glucoside as crystalline, but not enough was obtained for proper 
investigation. Later, Zuco (299) described the method he used in 
obtaining the alkaloid, called chrysanthemine, from Pyrethrum 
flowers. Ten kilograms of flowers were boiled in distilled water for 
2 or 3 hours, filtered through cloth, the residue pressed and treated 
again in the same manner. The extracts were evaporated down to 
30 liters, treated with neutral lead acetate and basic lead acetate, 
neutralized with soda, filtered, and the excess of lead removed by 
passing hydrogen sulphid. After filtration, the liquid was concen- 
trated to about 2 liters, boiled for some time with dilute sulphuric 
acid, filtered again, and boiled until no more resinous matters were 
formed. The liquid was then decolorized with animal black, and an 
excess of the double iodid of potassium and bismuth added, which 
precipitated a heavy bright red crystalline powder. From this the 
alkaloid was obtained. According to Zuco this is a colorless sirup, 
soluble in water and in alkalis, soluble in ethyl and methyl alcohol, 
but not in ether, chloroform, or benzene. The base is described as 
being optically inactive and physiologically innocuous. The work 
of Zuco thus shows that the active insecticidal agent of Pyrethrum 
flowers is not alkaloidal in nature. 
Eymard (77), in 1890, distilled a mixture of insect powder with 3 
parts of water. The distillate was slightly opaline, held in suspen- 
sion a small quantity of "essence," and presented a strong and 
characteristic odor of Pyrethrum flowers. Tested upon ants and 
other insects, however, the distillate was found to have no effect, 
from which Eymard concludes that the essential oil is not the active 
insecticidal agent of insect powder. 
An ether extract was made, deep yellow and strongly odorous. 
It gave up nothing to water, but was completely soluble in 95 per 
cent alcohol and in alkalis. From alkaline solution it was precipi- 
tated by acid. From 110 grams of insect powder Eymard obtained 
