1893.] Arrow-Poison of the Wa Nyika and other Tribes. 



153 



As the experimental observations supply data for the calculation of 

 the emissive power of the surfaces of the bars at different tempera- 

 tures, a table is given at the end of the paper showing the emissive 

 power of the surface of each bar at temperatures between 20° C. and 

 200° C. The values obtained agree fairly with those given by Mac- 

 far] ane and Tait for somewhat similar surfaces. 



V. "Preliminary Notice on the Arrow-Poison of the Wa Nyika 

 and other Tribes of East Equatorial Africa, with special 

 reference to the Chemical Properties and Pharmacological 

 Action of the Wood from which it is prepared." By 

 Thomas R. Fraser, M.D., F.R.S., Professor of Materia 

 Medica in the University of Edinburgh, and Joseph Tillie, 

 M.D. (Edin.). Received March 6, 1893. 



Burton,* Cameron, f and other travellers have given accounts of 

 much interest of "an arrow-poison used in warfare and in the chase by 

 the Wa Nyika, Wa Kamba, Wa Gyriama, and other tribes of Eastern 

 Equatorial Africa. The poison was stated to be prepared from the 

 wood of the stem and root of a tree, which, however, was not 

 botanically identified. 



Several years ago, an opportunity was given to one of us to examine 

 poisoned arrows, and the poison used in smearing them, of the Wa 

 Nyika tribe. While the pharmacological action of this poison was 

 found to have a close resemblance to that of Strophanthus seeds, its 

 physical and chemical properties enabled the conclusions to be drawn 

 that the poison was not made from these seeds, but was chiefly com- 

 posed of an extract prepared from a wood .J 



These conclusions have been confirmed by the examination of 

 further specimens of the Wa Nyika arrow-poison, and of the wood 

 from which it is prepared. The specimens were most kindly sent to 

 one of us, at various times between 1889 and 1892, by the Rev. 

 William Morris, of the Church Missionary Society's East African 

 Mission, and by Mr. Berkeley, the Administrator to the Imperial 

 British East Africa Company at Mombasa. 



These gentlemen have also sent the leaves and fruit of the plant, 

 which have enabled us to identify it as an Acohanthera ; but, as 

 flowers have not yet been obtained, it has not been possible to deter- 

 mine the species. 



* ' The Lake Regions of Central Africa,' 1860, vol. 2, p. 305. 

 f 1 Across Africa,' 1885, p. 59. 



X Fraser, "On Strophanthus Mspidws : its Natural History, Chemistry, and 

 Pharmacology," ' Edinburgh Eoy. Soc. Trans.,' vol. 35, Part IV, 1890, pp. 966-67. 



