TWENTY-FIVE YEARS OF CHEMICAL INVESTIGATION. 99 



full account of the Cape laboratory investigations in this con- 

 nection will be found in my " Notes Regarding South African 

 Pharmacology," the paper quoted above as having been com- 

 municated to the South African Philosophical Society in 1905. 



In addition to alkaloids and glucosides, poisonous glucosidal 

 resins and allied bitter principles have been found in a variety 

 of indigenous plants. For instance, the dried root of Polygonum 

 tomcntosuui, var. glabrum, was found to contain two and a half 

 per cent, of an acrid resin possessing characteristic chemical 

 colour reactions, and acting physiologically as a powerful de- 

 pressant. The plant is made into a decoction by the natives in 

 Temibuland and applied remedially in the cattle disease known 

 as black-gall sickness. x'\s far as could be seen from the fe\v 

 physiological experiments that it was found possible to under- 

 take, the active principle of the plant exerts a paralytic effect 

 on the muscles of the heart, eventually arresting that organ in 

 systole. On mice it proved rapidly fatal, and the probability 

 if that on human beings a sufficient dose would have a similar 

 effect: in fact, it was the death of a native girl at Kingwilliams- 

 town that led to the undertaking of this investigation. 



A similar fatality led to an examination of Hceiiwntlvis 

 iiataloisis bulbs. From these bulbs .168 per cent, of a yellowish 

 non-crystallisable substance was extracted, and, after a series of 

 physiological experiments had been made, the conclusion arrived 

 at was that the plant is not directly poisonous, but produces 

 rapid emesis accompanied by violent straining, which, in the case 

 of constitutions not robust enough to withstand the effects, may 

 well prove fatal. 



In 1907 a bulb known to the natives as tynmfyiunana, but 

 which it has hitherto been impossible to identify botanically, 

 was investigated and found to contain a resinous body possessing 

 well-defined and characteristic chemical reactions. The resin 

 was bitter and acid in character, and a woman was proved to 

 have died after partaking of the bulb. Physiological tests on 

 animals abundantly proved its rapidly acting toxic nature. Three 

 years later a herbal decoction prepared by a Kafir doctor came 

 under notice of the laboratory at Grahamstown, and was found 

 to possess a peculiar herbal odour which at once associated it 

 with the tyumtyuniana of the 1907 investigations. A resinous 

 substance was extracted from it. yielding chemical reactions 

 identical with those then observed, and the effect on the heart 

 and blood — for a person had died after drinking of the decoction 

 — was also similar to that resulting from the administration of 

 the iyumtyumana. 



A year after the first experiments with the tyumtyuniana 

 bulbs, an investigation was begun of another bulb, called usiga- 

 gana by the natives, and no less than nine months were spent 

 unsuccessfully in endeavouring to procure a specimen with leaves 

 and flowering stalk complete for botanical identification. In this 

 case, too, severe physiological experiments showed that severe 

 emesis set in rapidly after administration, terminating fatally. 



