480 ON THE PITYSIOLOGICAL ACTION OF NITHO-GLYCErJKE. 



from an animal poisoned witli nitro-glycerine, or of normal 

 blood shaken up with it, and normal blood, either before or 

 after the addition of a reducing fluid. If our observation 

 "were correct, this would constitute an important difference 

 between nitro-glycerine-blood and nitrite- blood as described 

 by Gamgee ; but the strong similarity in colour between the 

 two kinds of blood makes us doubtful about the correctness of 

 our spectroscopic observation, and we hope to repeat it with a 

 better instrument as soon as opportunity allows. 



Action on Oxidation. — Certain vegetable substances have tlie 

 povver of oxidising tincture of guaiac, and causing it to become 

 blue. In order to ascertain whether nitro-glycerine had any 

 power to diminish or prevent this oxidising process, a potato 

 was pounded with water, and the liquid strained off and mixed 

 with tincture of guaiac and a small quantity of nitro-glycerine. 

 Instead of preventing oxidation, however, it rather seemed to 

 quicken it, the mixture assuming a blue colour more quickly 

 and more intensely than where no nitro-glycerine was added. 

 in this respect also its action resembles that of nitrites as 

 described by Binz and Pick. 



From our experiments it would then appear that nitro- 

 glycerine agrees with nitrites in not lessening the oxidation of 

 guaiac by vegetable solutions, in causing tlie blood of animals 

 poisoned by it to become of a chocolate colour, in acting as a 

 muscular poison, and in diminishing blood-])ressure. Its action 

 in this last respect is, however, much less than that of nitrite 

 of amyl. In a future paper we hope to give a more detailed 

 and complete account of the action of nitro-glycerine, and of 

 the resemblances and differences between its action and that of 

 aiitrites, as well as a discussion of its possible use in medicine. 



Note. — The severity of the headache which nitro-glycerino 

 induced in one of us (Brunton) was so great that it made us 

 delay in trying it on patients, and before wo had done this it 

 was proposed by Dr. Murrell as a substitute for nitrite of aniyl. 

 W.Murrell: "Nitro-glycerine as aEemcdy for Angina Pectoris," 

 Zancct, 1870, i, 80, 113, 151, 225. 



