Fisn POISONING AND POISONS.— HAMLYN-HAEBIS AND SMITE. 13 



The experiments of Hanriot dealing with the action of tephrosin, the 

 poisonous principle of T. vogdid, show that "when a fish is placed in a dilute 

 solution it shows great excitement at first but soon becomes quiet. The fins lose 

 colour and become paralysed and the fish turns over and eventually dies." 

 Our experimental results with T. rosea and T. purpurea are in agreement except 

 that no paling of the fins could be observed. The action is extremely rapid. 



The Occurrence of Tephrosin in T. rosea and T. purpurea. 



Hanriot has isolated from T. vogelii a poisonous principle, tephrosin 

 (M. Pt. 187° C.),^^ a volatile oil, tephrosal, and an uncharacterised yellow body; 

 and more recently his results have been confirmed on material from Rhodesia in 

 the laboratories of the Imperial Institute. Experimental work on T. rosea and 

 T. purpurea demonstrates the presence of probably identical bodies in these 

 species. Following substantially the method of Hanriot, extraction with alcohol 

 and distillation of the extract in steam, a pungent yellow oil passed over which 

 is thought to be identical with tephrosal. The evaporated residue is treated with 

 chloroform, and the chloroformic solution precipitated with ether. Resinous 

 bodies are removed by agitation with aqueous alkali, and the ether-chloroform 

 solution evaporated. The residue was found to be yellowish and hemi-crystalline, 

 and the residue from evaporation of acetone solution is also markedly crystalline ; 

 the crystals being associated with a yellow body from which is was impracticable, 

 with the material available, to completely separate them. 



Concerning the toxicity of the final product there can be no doubt; a 

 concentration approximately 1 : 1,000,000 proved fatal to test fish in half an hour. 



PONGAMIA GLABRA, Vent. 



The plant is recorded by Roth as a Queensland native fish-poison as 

 follows: — " After being roasted, the roots are beaten upon a stone, tied in bundles 

 and thrown into the water which turns somewhat greenish; it is put in of an 

 evening and left there all night." 



Botanically allied to Derris and Piscidia — the latter given as a fish-poison 

 by Greshoff— its action is rapid and effective, the leaves being only less potent 

 than the root. The active principle is found to reside in the ether extract of the 

 root, and may be identical with or allied to the pachyrhizid, timboine, and 

 tephrosin of other leguminous plants. Its failure to give a blood-red colouration 

 with sulphuric acid and ferric chloride distinguishes it from derrid of genus 

 Derris. 



ALBIZZIA PROCERA, Benth. 



A. procera was received by us through Sergeant Geary, described as an 

 Acacia, from the Proserpine district, with the statement that the inside of the 

 bark alone is used. The specimen did not prove certainly effective, the 

 physiological effect being slight. Lauterer^- and Bancroft'^ have, however, 

 pointed out the transitory nature of the occurrence of saponin in the plant, and 

 in certain Acacias, and at seasons more positive results would probably have been 

 obtained. It is scarcely credible, though, that the aboriginal could distinguish 

 periods of maximum effectivity, and Alhizzia would probably in his hands con- 

 stitute an uncertain instrument. 



^ «i Bull. Imp. Institute, vol. 13, No. 1, 1915. ' - 

 'Vx^*^ Joseph Lauterer, Occurrence of Saponin in Australian Acacias & Alhizzias, Proc. 

 Roy.'Soc. Q., vol. 12, 1896, p. 101-7. 



f^h.' ^^ T. L. Bancroft, On the Discovery of Saponin in Acacia delibrata, Cvmn., Proc. Roy. 

 Soc. Q., vol. 4, 1887, p. 10. 



