964 DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 



length ; its straight portion is furnished with two curved and strong spikes pointing 

 downwards and having sharp points ; and the true arrow-head is 2^ inches long, 

 elegantly shaped, with a fine tapering extremity and sharp barbs, and with one lateral 

 half of each surface concave and the other convex. The poison covers, in a layer of from 

 |th to T Vth of an inch in thickness, the whole of the exposed straight portion of the 

 barb and the two spikes projecting from it, and also the true arrow-head with the 

 exception of its point and edges. This poison is of a dark greyish-brown colour, and 

 is earthy, though rather tough, in consistence. Only a small portion of it is soluble in 

 water, the solution being faintly acid, bitter, and of a light sherry colour ; the remaining 

 undissolved portion appearing under the microscope as a granular debris in which frag- 

 ments of vegetable tissue, numerous pieces of vegetable hairs, and oil globules could be 

 distinguished. 



When examined chemically, the poison produced with solution of potash a faintly 

 yellow fluid, in which pinkish or brownish particles were suspended ; and when heated 

 between 116° and 120° F. along with 10 per cent, sulphuric acid, it gradually acquired 

 a greenish colour, which passed into light brown. 



When O'l grain was thoroughly mixed with four or five drops of distilled water, a clear 

 almost colourless solution was obtained, having a slightly bitter taste. This solution was 

 injected under the skin of a frog weighing 420 grains, and it produced the disorders of 

 motility, fibrillary twitches of muscles, and paralysis of respiration, which are observed 

 under the action of Strophanthus. The heart was exposed one hour and forty-five 

 minutes after the poison had been injected, and it was found to be in complete standstill, 

 with the ventricle small and mottled, and the auricles dark and somewhat distended; 

 and mechanical irritation applied to the ventricle and auricles failed to excite movement 

 of any part of the heart. For some time after complete paralysis of the heart, active 

 general reflex movements could be excited by slight irritation. 



Arrow B (see Plate I.) is one of the four tied along with arrow A, and its form is the 

 same as that of other two of these four arrows, and altogether different, as the illustration 

 shows, from the fourth arrow, or arrow A. Arrow B also closely resembles the arrow already 

 referred to (pp. 957 and 961) as having been obtained in Bishop Mackenzie's Expedition, 

 and described by Livingstone.* This circumstance probably indicates that the arrows A 

 and B had also been obtained from the neighbourhood of the River Shire or of Lake Shirwa. 



Arrow B is 37 inches in length. The cane portion of the shaft has no feathers, but 

 they seem to have been removed along with several inches of the extremity of the shaft. 

 The head is of iron, and consists of a long nearly straight portion inserted into a hollow 



* An illustration has not been given of this arrow, as it is the same in every important detail as arrow JB. The 

 physical characters of the poison are also the same, and it also consists structurally of fragments of vegetable tissue, 

 amorphous yellowish-brown granular matter, oil globules, and incomplete vegetable hairs. The solution obtained by 

 macerating and triturating one-tenth of a grain with water, somewhat quickly produced, in a frog weighing 329 grains, 

 muscular weakness, gaping movements of the mouth, fibrillary twitches, and stoppage of pulmonary respiration. Thirty- 

 six minutes after the solution had been injected, the exposed heart was found to be motionless, with the ventricle con- 

 tracted, and the auricles large and dark, and no movement of the heart could be excited by mechanical irritation, 

 although general, but feeble, reflex movements still followed irritation of the skin. 



