CONCERNING THE EFFECTS OF "TUBA" FISH-POISON. 135 



of the extract should he added to the pool to make the water cloudy. 

 Of course this would kill fish up to 50 gm. far more quickly than 

 it would the larva and in time it would certainly affect much 

 larger fish. 



Its effects on the higher animals can be explained from the 

 results obtained in the experiments performed on anaesthetised 

 animals. The great weakness exhibited in cases of poisoning is 

 due to the fall of blood pressure and to the weakening of the 

 voluntary and involuntary muscle. The effects on the respiration 

 are due at first to the stimulation and afterwards to the paralysis 

 of the respiratory centre. The vomiting which usually occurs seems 

 to be due to the stimulation of the vomiting centre in the medulla. 

 After injection of the poison into the stomach whatever the dose 

 a definite interval elapses before vomiting takes place. It occurs 

 at the same time as the other changes and it is never excessive. 

 Even after vomiting death takes place thus showing that sufficient 

 poison is absorbed before vomiting occurs. 



From the facts that the animal remains conscious and that 

 the reflexes are present until the respiratory centre is greatly 

 affected, it follows that the poison has no previous effect on other 

 parts of the brain and spinal cord. The animals do become sleepv 

 but that can be explained by the muscular weakness and the fall 

 of the blood pressure. The unconsciousness and absence of reflexes 

 come on during the asphyxia. 



It has already been mentioned that cases of abortion with 

 fatal haemorrhage have occurred by the use of this poison. The 

 poison does not act directly on the uterus since it weakens in- 

 voluntary muscle. The abortion must be due to the asphyxia 

 produced by the poison. The uterine haemorrhage is due to the 

 dilatation of the blood vessels. 



The poison is very virulent since the extract from only 2 gm. 

 (30 grains) of the root is sufficient to kill a large monkey. Cases 

 of murder have not been reported probably because the would-be 

 victim detects the presence of something to be avoided owing to 

 the acrid taste and smell of a strong solution. Cases of suicide 

 have been reported. A few months ago a case of suspected " tuba " 

 poisoning was recorded in Singapore. I am indebted to Dr. E. D. 

 Keith acting Government Pathologist for the details. A quantity 

 of " tuba " root was found in the room with the body. Post Mortem 

 examination revealed nothing but venous congestion of the organs. 

 The lungs possessed an acrid odour. Analysis of the stomach con- 

 tents was negative. " Tuba " poison was not tested for, because 

 chemical tests for this poison are unknown, although Greshoff (3) 

 describes crystals of definite shape and colour, which are obtained 

 from the poison. 



The Post Mortem examinations in my experiments only show 

 venous congestion of the organs. 



E. A. Soc, No. 73, 1916. 



