1864.] 



Chemical Agents upon Blood, 



159 



4. The influence of hydrocyanic acid was studied both upon ox-blood 

 and human blood, and found to be the same in each case, namely, to 

 arrest respiratory changes. 



5. Nicotine was also found to diminish the power of the blood either to 

 take up oxygen or give off carbonic acid gas and thereby become fitted for 

 the purposes of nutrition. 



6. The effect of woorara poison, both on the blood in the body and out 

 of it, was ascertained to be in some respects similar to that of snake-poison, 

 namely, to increase the chemical decompositions and transformations upon 

 which the exhalation of carbonic acid depends ; but differed in retarding, 

 instead of hastening, the oxidation of the constituents of the blood. 



7. Antiar poison and aconite were found to act aUke, inasmuch as both 

 of them hastened oxidation and retarded the changes upon which the 

 exhalation of carbonic acid depends ; in both respects offering a striking 

 contrast to woorara poison, which, as has just been said, diminishes oxida- 

 tion and increases the exhalation of carbonic acid. 



8. The effect of strychnine on the blood, both in and out of the body, 

 was studied, and found to be in both cases identical, namely, like some of 

 the other substances previously mentioned, to arrest respiratory changes. 

 Moreover, in one experiment in which the air expired from the lungs of an 

 animal dying from the effects of the poison was examined, it was ascer- 

 tained that the arrest in the interchange of the gases took place before the 

 animal was dead. 



9. Brucine acts in a similar manner as strychnine, but in a much less 

 marked degree. 



10. Quinine also possesses the power of retarding oxidation of the blood, 

 as well as the elimination of carbonic acid gas. 



1 1 . Morphine has a more powerful effect in diminishing the exhalation 

 of carbonic acid gas, as well as the chemical changes upon which the 

 absorption of oxygen by blood depends. 



Under this head the effects of ansesthetics upon blood are next detailed ; 

 and in the first place, the visible effects of chloroform upon blood are thus 

 described : — If 5 or more "per cent, of chloroform be added to blood, and 

 the mixture be agitated with air, it rapidly assumes a brilliant scarlet hue, 

 which is much brighter than the normal arterial tint, and is, besides, much 

 more permanent. When the mixture is left in repose, it gradually solidi- 

 fies into a red-paint-like mass, which when examined under the micro- 

 scope is frequently found to contain numerous prismatic crystals of an 

 organic nature. If the blood of an animal poisoned from the inhalation of 

 chloroform be employed in this experiment, the paint-like mass will be 

 found to be composed in greater part of the crystals just spoken of ; the 

 crystals in this case being both larger and finer than when healthy blood is 

 employed. Chloroform only partially destroys the blood-corpuscles. Its 

 chemical action is to diminish the power of the constituents of the blood to 

 unite with oxygen and give off carbonic acid. 



