I performed some experiments in 1848,[[161]] for ascertaining the proportions of vapour of ether present in the blood in the different degrees of narcotism. They were conducted on the same principles as those previously related, which were performed for the purpose of determining the same point in regard to chloroform.
Experiment 31. Two grains of ether were put into a jar holding 200 cubic inches, and the vapour diffused equally, when a tame mouse was introduced, and allowed to remain a quarter of an hour, but it was not appreciably affected.
Experiment 32. Another mouse was placed in the same jar, with three grains of ether, being a grain and a half to each 100 cubic inches. In a minute and a half, it was unable to stand, but continued to move its limbs occasionally. It remained eight minutes without becoming further affected. When taken out, it was sensible to pinching, but fell over on its side in attempting to walk. In a minute and a half, the effect of the ether appeared to have gone off entirely.
Experiment 33. A white mouse in the same jar, with four grains of ether, was unable to stand at the end of a minute, and at the end of another minute ceased to move, but continued to breathe naturally, and was taken out at the end of five minutes. It moved on being pinched, began to attempt to walk at the end of a minute, and in two minutes more seemed quite recovered.
Experiment 34. Five grains of ether, being two and a half grains to each 100 cubic inches, were diffused throughout the same jar, and a mouse put in. It became rather more quickly insensible than the one in the last experiment. It was allowed to remain eight minutes. It moved its foot a very little when pinched, and recovered in the course of four minutes.
Experiment 35. A white mouse was placed in the same jar with six grains of ether. In a minute and a half, it was lying insensible. At the end of three minutes, the breathing became laborious, and accompanied by a kind of stertor. It continued in this state till taken out, at the end of seven minutes, when it was found to be totally insensible to pinching. The breathing improved at the end of a minute; it began to move at the end of three minutes; and five minutes after its removal, it had recovered.
Experiment 36. The same mouse was put into this jar on the following day, with seven grains of ether, being 3·5 grains to the 100 cubic inches. Stertorous breathing came on sooner than before; it seemed at the point of death when four minutes had elapsed; and being then taken out, was longer in recovering than after the last experiment.
Experiment 37. Two or three days afterwards, the same mouse was placed in the jar, with eight grains of ether, being four grains for each 100 cubic inches. It became insensible in half a minute. In two minutes and a half, the breathing became difficult; and at a little more than three minutes, it appeared that the breathing was about to cease, and the mouse was taken out. In a minute or two, the breathing improved; and in the course of five minutes from its removal, it had recovered.
The temperature of the mice employed in the above experiments was about 100°. That of the birds in the following experiments was higher, as is stated; and they differ widely from the mice in the strength of vapour required to produce a given effect, although I found but little difference between the mice and birds, in this respect, in the former experiments on chloroform. And one of the linnets was employed in both sets of experiments. Having seen MM. Dumeril and Demarquay’s statement of the diminution of animal temperature from inhalation of ether and chloroform, before the following experiments were performed, the thermometer was applied at the beginning and conclusion of some of them. I have selected every fourth experiment from a larger series on birds.
Experiment 38. 18·4 grains of ether were diffused through a jar holding 920 cubic inches, being two grains to each 100 cubic inches, and a green linnet was introduced. After two or three minutes it staggered somewhat, and in a few minutes more appeared so drowsy, that it had a difficulty in holding up its head. It was taken out at the end of a quarter of an hour, quite sensible, and in a minute or two, was able to get on its perch. The temperature under the wing was 110° before the experiment began, and the same at the conclusion.