Sept. 3, 1517 Quassia Extract as a Contact Insecticide 499 



material is "rubbed," the solvent action of the cold water is greater 

 than that of either hot or boiling water, the high temperature in the case 

 of the latter resulting in an oxidation and consequent insolubility of the 

 bitter principle. 



In 1822 Morin (25), working wuth the bark of Quassia simaruba, 

 reported the presence of quassiin and a volatile oil having an odor of 

 benzoin. 



In 1829 Fechner (10) came to the conclusion that "rubbing" facili- 

 tated the extraction of quassiin from Quassia excelsa and that boiling is 

 of no benefit. In 1835 Winckler (48) made an exhaustive study of 

 Quassia amara, contributing much to the information already acquired 

 concerning quassiin. He considered quassiin to be of a basic nature, 

 but later investigators proved that it is not a true base. The experi- 

 ments of Kellar (19) in the same year, while not conclusive, raised the 

 question as to whether quassia contained an alkaloid. Two years later 

 Wiggers (47) pointed out that quassiin was of a nonbasic character. 

 He also outlined in general the properties of quassiin, including its solu- 

 bility in water, which he found to be 0.45 part in 100. This seems to 

 be much greater than the actual solubilit}^ but his results may have 

 been influenced by impurities, which he himself claimed will increase 

 solubility. The substance obtained he called "quassit," the ending "it" 

 being used to indicate its nonbasic character. 



In 1858 Rochelder (38) recorded the fact that both Simaruba amara 

 and Simaruba cedron contain a crystallizable bitter principle similar to 

 quassiin. In 1868 Enders (9) asserted that quassia was used as a sub- 

 stitute for hops in brewing. In his study he found quassiin to be almost 

 insoluble in water, readily soluble in alcohol and chloroform, and insoluble 

 in ether. He concluded that the toxic principle was not a glucosid and 

 found that it was precipitated by tannic acid. 



In 1882 Christensen (4) obtained 12 gm. of what he considered pure 

 quassiin from 18 kgm. of Picraena excelsa. This is equivalent to a 

 solubility of i to 1,500. The solubility in warm water was found to be 

 less than that in cold water. 



In 1884 Oliveri and Denaro (26-29) undertook experiments to deter- 

 mine the molecular structure of the quassiin molecule. In 1889 Dymock 

 and Warden (7) investigated Picrasma quassioides, a native of China 

 and the subtropical Himalayas, and found the bark and wood to be as 

 bitter as quassia. A crystallizable principle was isolated which resem- 

 bled quassiin. An alcoholic extract gave positive reactions with alka- 

 loidal reagents. No pharmacological effects were found. In 1890 

 Dymock, Warden, and Hooper (8) in their Pharmacographia Indica 

 quote Stewart as stating that the wood of Picrasma quassioides was 

 used in the Punjab to kill insects. In the same year Massute (23) pub- 

 lished his researches on the chemical constituents of Quassia amara and 



