1889.] Physiological Action of Seeds of Abrus precatorius. 99 



25 minutes, and 37 minutes after toe inoculation. In only two cases 

 have we noticed any effect; in both these there was a very slight and 

 gradual fall in the blood pressure. In one of these cases a dose of 

 0*044 gram per kilo, of body weight was injected into the femoral 

 vein, and in the other a dose of only 0*0042 gram per kilo. 



There is, therefore, no marked effect on the blood pressure, nor on 

 the inhibitory power of the vagus, such as we noticed on the body 

 temperature. The only immediate evident effect of abrus-poisoning is 

 a fall of the temperature ; symptoms of weakness and of rapid respi- 

 ration only appear much later, from five to twelve hours after the 

 subcutaneous inoculation, according to the dose given. 



Effect of Heat on the Physiological Action of Abrus-globulin. — 

 Boiling destroys the activity of a watery extract of abrus seed. We 

 have performed many experiments with the view of determining a1 

 exactly what temperature the activity of the poison is destroyed. It is 

 reasonable to suppose that if the chief poisonous principle of abrus 

 seed is the globulin, that the activity would be destroyed at the tem- 

 perature at which the globulin coagulates ; and this we have found to 

 be the case. 



The Poisonous Action of Abrus-globulin is completely destroyed by 

 momentarily heating a Solution to a Temperature of 75° or 80° 

 the Temperature at which the Globulin coagulates. 



The heating was done in a test-tube placed in a water-bath; as 

 soon as the solution of globulin was at the required temperature, the 

 tube w r as removed and rapidly cooled. 



In one experiment, four rats were inoculated with the same dose of 

 globulin, which in one case had been heated to 50° C, in another to 

 60° C, in the third to 70° C, whilst the fourth was unheated ; all the 

 animals died with symptoms of abrus-poisoning within thirty hours of 

 the inoculation. In another experiment, three rats were inoculated, the 

 first with a solution of globulin heated to 75° C, the second with the 

 same amount heated to 80° C, whilst the third was inoculated with 

 unheated globulin. The first two rats, those inoculated with solutions 

 heated to 75° and 80° C, remained quite well, while the third, 

 inoculated with unheated globulin, died within twenty-four hours of 

 abrus-poisoning . 



Experiments performed on the eye with solutions of globulin, 

 similarly treated, gave the same results ; if heated up to 50°, 60°, or 

 70 13 C, the globulin produces as intense an ophthalmia as when un- 

 heated, but if heated to 75° or 80°, the globulin produces no inflamma- 

 tion or oedema. 



The conclusions, therefore, at which we have arrived from our 

 experiments are — 



H 2 



