INSECT POWDER. 69 



yellow crystals and had a melting point of 70° to 100°. Ahev repeated 

 recrystallization from cold ether a parafFm, (\^1{.^^^, 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 recrystalhzed 

 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 Chrysantliem.mn cinerarisefolium. 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 Pja-ethrum 

 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 Uters, boiled for some time with dilute sulphm-ic 

 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 either, 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 Pyrethrmn 

 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 opahne, held in suspen- 

 sion a small quantity of "essence," and presented a strong and 

 characteristic odor of Pyi-ethi'um 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 



