972 DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 



barb on each side, originating near the junction of the lowest third with the middle third 

 of the head. 



The poison is plastered over each surface of the head in a thick layer, for the most 

 part -g-th of an inch thick, which covers the whole head, excepting its margins and the 

 spike-like barbs. It is tough and hard, dark brown on the surface, and ochry-brown in 

 the interior. It is partly soluble in water, and gives a slightly gritty sensation when 

 triturated with it ; and the watery solution is nearly colourless, acid in reaction, and 

 distinctly bitter. 



On microscopic examination, the poison was found to consist of vegetable tissues, 

 pieces of vegetable hairs, oil globules, and brown granular masses. Solution of potash 

 caused it to become yellowish-brown in colour ; and, after it had been added, numerous 

 microscopic, oval or kidney-shaped, colourless bodies made their appearance in the 

 mixture. When heated between 110° and 120° F. with 10 per cent, sulphuric acid, 

 it became green, and some time afterwards a faint violet tint could be detected. 



The solution obtained by triturating xV^ n °f a g ram with 4 minims of distilled water 

 was injected under the skin of a frog weighing 325 grains. In a short time the peculiar 

 attitude of Strophanthus poisoning was assumed, the mouth was frequently opened, the 

 respirations became slow, the pupils contracted, fibrillary twitches occurred, voluntary 

 movements were enfeebled, and the skin became paler in colour. The heart was exposed 

 thirty-six minutes after the poison had been injected; it was found to be motionless, with 

 the ventricle small and mottled, and the auricles large and dark, and irritation of any 

 part of the heart failed to excite contraction. Twenty minutes afterwards, general and 

 feeble reflex movements followed irritation applied to the skin. [At no time during 

 the experiment were there any spasms, nor were the reflex movements in the slightest 

 degree exaggerated. 



It appeared that some assistance might possibly be obtained in the identification of 

 the poison of the arrows and in the packet, by determining whether a glucoside were 

 present in any of them, especially as the active principle of Strophanthus is a glucoside. 

 It was, however, found that this assistance could not easily be obtained, for each of the 

 poisons reduced Fehling's solution before the poison had been digested with an acid. 



In Table I. (p. 973) the results of the examination of the arrow-poisons have been 

 summarised. 



From the above experiments I am led to conclude that the poison of arrows A, B, 

 E, F, G, and H consists principally, if not entirely, of a substance made with the seeds of 

 Strophanthus. In reference to arrow C, no results were obtained sufficient to identify the 

 substance with which it had been poisoned ; nor, in the meantime, can any more definite 

 statement be made with regard to arrow D than that its poison is a substance closely 

 resembling Strophanthus in pharmacological action. This substance also sufficiently 

 resembles the poison contained in the packet J to lend confirmation to the statement of 

 the natives of the Wanyika tribe, that the poison in the packet is the same as that applied 

 to the arrow D. If this poison be prepared from Strophanthus seeds, the seeds must have 



