STRYCHNINE — CARBONIC OXIDE. 08 3 



several deep breaths, and repeat the experiment. He will now 

 notice that for several seconds more than on the first trial he 

 does not feel any inclination to breathe at all. This is the state 

 of apnoea as understood by physiologists. A few years ago, 

 Eosenthal and Leube* discovered that, when rabbits were kept 

 in this condition by means of artificial respiration, a fatal dose 

 of strychnia might be injected subcutaneously without producing 

 any effect. When the respiration was discontinued, and the 

 animal was allowed to pass from the state of apnoea, convul- 

 sions came on even after the respiration had been kept up for 

 as much as three hours. If it were continued for three and a 

 half or four hours, however, the strychnia seemed to have 

 been destroyed or excreted, and respiration might be discon- 

 tinued without the occurrence of any convulsion whatever. 

 That the lives of the animals had really been saved by artificial 

 respiration was shown by the fact that they died when a similar 

 dose of strychnia was given to them some time afterwards, and 

 respiration was not used. A year afterwards, another of Eosen- 

 thal's pupils — Uspensky — showedf that strychnia was not the 

 only poison the action of which could be prevented by artificial 

 respiration. The convulsive action of brucia, thebaia, and 

 caffeine was abolished in an exactly similar manner; but no 

 influence could be observed upon that of picrotoxin and nicotia. 

 The examples already given are sufficient to prove that life 

 may often be preserved by means of artificial respiration alone, 

 both in injury and in poisoning. If a man be found lying 

 insensible in a close room, poisoned by the fumes of a charcoal 

 fire, he can generally be restored by respiration if his heart be 

 still beating. But this is not always the case ; for the charcoal- 

 fumes contain carbonic oxide, which unites witli the colourino- 

 matter of the blood, and prevents it from taking up oxygen ; 

 so that it may pass time after time through the lungs, and yet 

 remain venous. It is true, that after a while the carbonic oxide 

 will be expelled from the blood, which then will become capable 

 of taking up oxygen as usual; but the heart may stop, and 

 all hope of recovery be lost before this can be effected, if the 



* Reichert and Du Bois Rejmond's ArcMv., 1867, p 629. 

 t Op. cit., 1868, p. 522. 



