12'i REPORT— 1864. 



that this gentleman had been exposed to the vajjour derived from the escape 

 of twenty minima of the nitrite, much of which necessarily was lost by dis- 

 tribution in the air. 



In a long series of experiments I have submitted animals to the inhalation 

 of the nitrite, and with the most interesting results. I must, at the risk of 

 being tedious, give the salient points of observation. 



Into a jar capable of receiving 200 cubic inches of air, a large healthy 

 frog was placed, and ten minims of the nitrite were sloAvly introduced. 

 The animal, after exhibiting violent vascular action with reddening of the 

 feet, sank into a condition which so closely resembled death, that I thought 

 it was dead. At 11 o'clock at night it remained the same (the experi- 

 ment was made at 8 p.m.), and I laid it aside as dead; but I was struck 

 with one fact, that the eyelid was not contracted, as is common in these ani- 

 mals after dissolution : on the following morning, upon going into the labo- 

 ratory, I found the animal alive and as active as though nothing had happened 

 to it. 



Tliis observation led me natiu-ally to make many inquiries as to the con- 

 dition of frogs during this state of suspended animation ; and I found little 

 difficulty in obtaining a repetition of the phenomenon. The experiment 

 usually succeeds well, and the suspension of animation may, under proper 

 supervision, be sustained even for days. In one case an animal came back 

 to consciousness after nine days. The experimentalist miist, however, be 

 prepared for some failiu'es. Thus, if the frogs are not fresh and strong, if 

 they have been kept in confinement for some weeks, and are thin and feeble, 

 the experiment will fail ; or if after the cessation of motion the animal is left 

 too dry, so that he loses water, the experiment will not succeed ; or if the 

 amount of am yl -vapour given is too great, the experiment may not succeed. 



In six cases where the animals recovered, I made numerous observations. 

 Examining the web of the foot, T found that there was no sign of circulation 

 there. Laying open the thigh muscles and exposing them to continuoiis 

 galvanic current as well as to the induction-current, and to shocks from the 

 positive conductor of the friction-machine, I found no evidence of irritability. 

 Exposing the muscles to water warmed to various degrees, from 70° to 120° 

 Pahr., there was no evidence of irritability. The only circumstance that 

 would lead an observer to infer that death had not actually taken place, was 

 that the limbs remained flaccid. In cases where rhjor mortis came on, 

 although the animals would lie for many hours without undergoing decom- 

 position, they never afterwards showed signs of irritability, but idtimately 

 became flaccid and decomposed. 



On warm-blooded animals the nitrite produces conditions similar, but not 

 so extreme in character. Administered gradually by inhalation to a strong 

 rabbit until complete prostration was induced, I laid the animal on a (able 

 and found that the respirations were reduced to one per minute. The limbs 

 were flaccid and motionless ; and when they were moved and were laid in any 

 given position, there they remained. The pupils were widely dilated, and 

 the red portions of the body, as the mucous membranes of the moiith and 

 eyelids, were absolutely white ; the action of the heart could not be felt, nor 

 was it certain that the motion could be heard with the stethoscope. Cer- 

 tainly the two sounds were lost. In this condition, breathing softly but 

 sharply once in sixty or eighty seconds, the animal continued for two hours ; 

 then the breathing gradually rose. In throe hours and a quarter the action 

 of the heart could be felt by the hand ; in three liours there Avas movement 

 of the limbs, and in five hours the animal had recovered so as to be able to 



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