TRANSACTIONS OF THE SECTIONS. 223 



Sucli was an epitome of the facts placed before the author at the time when he 

 commenced to make his experiments. In setting- out on his own account, he first 

 prepared a standard solution of the hydrate. He found that 30 grains dissolved in 

 40 grains of water, and formed a saturated solution, the whole making up exactly 

 the fluid drachm. The standard solution prepared in this way was very con- 

 venient. 



The author next proceeded to inquire whether, hy the addition of the hydrate 

 to fresh blood, chloroform was liberated. This was proved to be the fact ; the 

 odour of chloroform was veiy distinct from the blood, and chloroform itself was 

 distilled over from the blood, and condensed by cold into a receiver. 



The narcotic power of the hydrate was then tried on pigeons, rabbits, and frogs. 

 The standard solution, named above, was employed, and was administered either 

 by the mouth or by hypodermic injection. The action was equally effective by 

 both methods. The general results were confirmatory of Liebreich's own expe- 

 rience to a very considerable extent. They are as follows : — In pigeons, weighing 

 from 85 to 11 ounces, narcotism was produced readily by the administration of 

 from I5 to 2^ grains of the hydrate. In these animals the doie of 2^ grains was 

 the extreme that coidd be borne with safety, and a dose of I5 grain was sufficient 

 to produce sleep and insensibility. The full dose of 2^ grains produced drowsiness 

 in a few minutes, and deep sleep with entire insensibility in twenty minutes. 

 Before going to sleep there was in every case, whether the dose was large or small, 

 vomiting. As the sleep and the insensibility came on, there was in every instance 

 a fall of animal temperatm-e, and even in cases where recovery followed, this de- 

 crease was often to the extent of five degrees. The respirations also fell in pro- 

 portion, declining in one case from 34 to 19 in the minute during the stage of 

 insensibility. From the full dose that could be borne by the pigeon, the sleep 

 which followed lasted from three and a half to four hours. Six hours at least was 

 required for perfect recovery. During the first stages of narcotism in pigeons the 

 evolution of chloroform by the breath was most distinctly marked. 



In rabbits weighing from 8-3 to 88 ounces, thirty grains of the hydrate were re- 

 quired in order to produce deep .sleep and insensibility. A smaller do«e caused 

 drowsiness and want of power in the hinder extremities, but no distinct insen- 

 sibility. 



When the full effect is produced in rabbits from the administration of the larg« 

 dose, the drowsiness comes on in a few minutes ; it is followed by want of power 

 in the hinder limbs, and in fifteen minutes by deep sleep and complete insensi- 

 bility. The pupil dilates, and becomes irregular ; the respiration falls (in one case 

 from GO to .39 in the minute), and the temperature declines 6° Fahr. ; sensibility 

 returns with the rise in number of respiratory movements, but in some cases falls 

 again during the process of recovery. The di'owsiness, or, if the animal is left alone, 

 what may be called sleep, lasts from five and a half to six hours. But it was ob- 

 served that the period of actual ansesthesia was very short, lasting not longer than 

 half an hour, after which the skin seemed rather more tlian naturally sensitive to 

 touch. During recovery there are tremors of the muscles almost like rigors from 

 cold ; they are due probably to great failure of animal temperature. 



In frogs a grain of the hydrate causes almost instant insensibility, coma, and 

 death. 



In further prosecution of his research, the author tested, on similar subjects, the 

 effect of chloroform, bichloride of methylene, tetrachloride of carbon, butylic 

 alcohol, and chloride of amyl. In all the observations with these substances, the 

 narcotizino- agent was used by hypodermic injection. It was found, as a result of 

 these inquiries, that 7 grains of chloroform, o of tetrachloride of carbon, and 7 of 

 chloride of amyl, produced the same physiological efl'ect as 2 grains of the hvdrate. 

 Seven grains of bichloride of methylene induced a shorter insensibilitv. A" rabbit 

 subjected to 30 grains of chloroform slept four hom-s and twenty-five minutes ; 

 and a pigeon subjected to 7 grains slept three hours and twenty-five minutes. All 

 these agents caused vomiting in birds, before the insensibility was pronounced, 

 the same as did the hydrate ; but in no animal was there any sign of the stage of 

 excitement which is seen when the same agents are administered by inhalation. 

 This fact is most important, as indicating the difference of action of the same 



