Experience gained during the war has thrown a certain amount of light upon this subject. Post-anæsthetic bronchitis and pneumonia was very prevalent among the wounded, far more so than among civilian patients. It is, the author believes, reasonable to attribute this fact to several causes. In the first place, the soldier’s life, alternating between stuffy billets and wet trenches, predisposed him to naso-pharyngeal catarrh of a fairly high degree of infectivity. Enthusiastic press representatives might state that you could not take cold so long as your feet and legs were always buried in half frozen mud, but experience hardly bore out their golden promises. Again, the soldier did not improve his catarrh by inveterate cigarette smoking. Lastly, military hospitals were large institutions, some under canvas, some in huts, some in buildings constructed for other purposes, and rapidly altered to the urgent needs of the army. Of whatever type, nearly all had one feature in common--many of the surgical wards were a long (and draughty) way from the operating theatre. For the prevention of post-anæsthetic pneumonia, the author offers the following tentative suggestions:-- (1) See that the skin is kept covered up as much as possible during the operation and that the patient is not exposed to draughts during or after it. Rooms can, and should be, well ventilated without cold draughts. (2) If a patient has an acute or sub-acute naso-pharyngeal catarrh, treat it as fully as possible before operation by sprays and gargles. (3) Do not use ether to patients who suffer or recently have suffered from such conditions. (4) Give a hypodermic of morphia and atropine before operation as a routine. (5) In so far as possible, let the patient’s shoulders and head be raised by pillows during the early hours of convalescence. (6) Lastly, remember that while no care will absolutely banish these dangerous sequelæ from our practice, the greater care and skill shown by the anæsthetist, the less bronchitis and pneumonia will appear among his patients. As regards ether, the author believes that it is the strength of vapour used, more than the duration of the anæsthesia, which counts. It is for that, among other reasons, that he has for the induction period, no hesitation in recommending a method whereby a small part of the requisite ether strength is replaced by chloroform. Vomiting. After an anæsthesia lasting more than a few minutes, it may almost be regarded as normal for the patient to vomit once or twice. Usually this occurs a few minutes after the administration has ceased. In the case of nitrous oxide and oxygen, even this slight disturbance may not occur.