70 Dr. T. R. Fraser. Acokanthera Schimperi : [Apr. 25, 



contain the argon lines as given by Mr. Crookes ; nor, with the 

 exception of the yellow line, do I get the special lines noted by him 

 in the gas. (Four of these out of six seem possibly to be due to 

 nitrogen.) 



But I do get lines nearly coinciding with chromospheric lines 

 discovered by me in 1868. 



On November the 6th of that year, I suspected a line less refrangible 

 than C, and so near it that when both were showing brilliantly the 

 pair appeared double, like D in a spectroscope of moderate dispersive 

 power.* 



Later, I discovered another line at 6678'3 (Rowland), which was 

 observed to vary with D 3 . There is a line in this position, with the 

 dispersion employed, in the spectrum of the new gas. This line has 

 also been seen by Thalen, as stated by Professor Cleve in a com- 

 munication to the Paris Academy (' Compfces Rendus,' April 16th, 

 p. 835), but the other lines given by him (with the possible exception 

 of the one at 501 6) have not been recorded by me. 



Although I have, at present, been unable to make final comparisons 

 with the chromospheric lines, the evidence so far obtained certainly 

 lends great weight to the conclusion that the new gas is one effective 

 in producing some of them, and it is suggested by the photographs 

 that the structure lines of hydrogen may also be responsible for some 

 of them. 



I may state, under reserve, that I have already obtained evidence 

 that the method I have indicated may ultimately provide us with 

 other new gases, the lines of which are also associated with those of 

 the chromosphere. 



Messrs. Fowler, Baxandall, Shackleton, and Butler have assisted 

 me in the various stages of the inquiry. 



III. "Acokanthera Sckimperi : its Natural History, Chemistry, 

 and Pharmacology." By THOMAS R. FRASER, M.D., 

 LL.D., F.R.S., Professor of Materia Medica in the 

 University of Edinburgh; and JOSEPH TILLIE, M.D., 

 F.R.S.E., Lecturer on Experimental Pharmacology in the 

 University of Edinburgh. Received March 28, 1895. 



(Abstract.) 



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 of East Africa. While the pharmacological 

 action of this poison was found to have a close resemblance to that 



* ' Phil. Trans.,' I860, p. 428. 



