45 



The principles of the root toxic to insects are the white 

 crystalline derivative, usually called "tubatoxin," and a resin of a 

 g-olden yellow colour identical with the "derride" of Sillevoldt. 



The dry root itself may be used in a finely powdered condition 

 worked up with water together with soap or other emulsifying- 

 reagfents. 



As the pure poisons found in derris root are solids and only 

 slig-htly soluble in water, their toxicity appears to depend upon 

 their degree of dispersion. 



A biological method of determining insecticidal properties 

 quantitatively is described. It depends on dipping insects for a 

 constant period of time in known strengths of highly dispersed 

 emulsions or suspensoids in dilute aqueous solutions of saponin. 

 Results agreeing with those given by the chemical method 

 described below were obtained, and it enabled a comparison to be 

 made between extracts of derris and nicotine. To certain cater- 

 pillars, tubatoxin and derride are shown to be of the same order of 

 toxicity as nicotine. 



XLIV. F. Tattersfield and W. A. Roach. "The Chemical 

 Properties of Derris Elliptica (Tuba Root)/' 

 Annals of Applied Biology, 192:1 Vol. X. 

 pp. 1-17. 



The toxic principles of Derris elliptica have been isolated and 

 some of the more simple properties examined. A chemical method 

 for evaluating the root has been outlined and a suitable extraction 

 apparatus described. 



The most important constituents of the root are a. white 

 crystalline derivative, usually called "tubatoxin," and a resin or a 

 series of resins identical with the "derride" of Sillevoldt and the 

 "tubain" of Wray. Besides these two, yellow crystalline deriva- 

 tives and a liquid resin were isolated. 



"Tubatoxin," the yellow crystalline deri\ativcs, and the resins 

 contain methoxyl groups and these compounds appear to be inter- 

 related. "Tubatoxin" by exposure to light, and by prolonged 

 boiling with organic solvents, is converted into three yellow 

 crystalline products and a resin. This suggests that the "anhy- 

 droderride" of Sillevoldt may ha\e been formed during the process 

 of extraction and may not exist as such in the root. 



The poisons from the root are readily extracted by means of 

 organic solvents. Ninety-five per cent, alcohol extracts them 

 together with non-toxic derivatives. Benzene, dry ether, carbon 

 tetrachloride are also good solvents for extraction purposes and 

 have a selective dissolving action on the poisons. Petroleum 

 derivatives are not suitable for complete extraction. Prolonged 

 boiling with solv^ents may cause some loss of toxicity in the 

 extracts owing to chemical change in the "tubatoxin." For 

 economic purposes, benzene and its congeners, or alcohol, are 

 probably the most suitable extraction reagents, provided the 

 temperature of extraction is not allowed to rise too high. 



The root mav be evaluated by chemical means by extracting 

 the dry root with dry ether, and the genuineness of the extracts 

 confirmed by the determination of the methoxyl content by the 

 Zeisel method. Extracts from different deliveries varied between 



