As an agent in labor where an anaesthetic is indicated, it is claimed by one who has employed it (Dr. Hews) in nearly every case for three years, he has used "rapid breathing" solely, and to the exclusion of chloroform and ether. For this I have his assertion, and have no doubt of it whatever, for if any agent could break down the action of the voluntary muscles of the parts involved, which prevent the involuntary muscles of the uterus from having their fullest effect, it is this. The very act of rapid breathing so affects the muscles of the abdomen as to force the contents of the uterus downward or outward, while the specific effect of the air at the end of a minute's breathing leaves the subject in a semi-prostrate condition, giving the uterus full chance to act in the interim, because free of the will to make any attempt at withholding the involuntary muscles of the uterus from doing their natural work. It is self evident; and in this agent we claim here a boon of inestimable value. And not least in such cases is, there is no danger of hemorrhage, since the cause of the effect is soon removed. In attestation of many cases where it has been tried, I have asked the mother, and, in some cases, the attendants, whether anything else had been given, and whether the time was very materially lessened, there has been but one response, and that in its favor. Gentlemen, if we are not mistaken in this, you will agree with me in saying that it is no mean thing, and should be investigated by intelligent men and reported upon. From my own knowledge of its effects in my practice, I am bound to believe this gentleman's record. I further claim for it a special application in dislocations. It has certainly peculiar merits here, as the will is so nearly subjugated by it as to render the patient quite powerless to resist your effort at replacing, and at the same time the pain is subdued. It is not necessary I should further continue special applications; when its _modus operandi_ is understood, its adaptation to many contingencies will of a sequence follow. It is well just here, before passing to the next point of consideration, to answer a query which may arise at this juncture: What are the successive stages of effects upon the economy from its commencement until the full effect is observed, and what proof have I that it was due to the amount of air inhaled?