In 1913, Karl Connell described such an apparatus, which was then in use at the Roosevelt Hospital, New York. The ether was vapourised by dropping it into a warm chamber. Air was pumped into the chamber, and carried the ether vapour in known percentage, and at known pressure as shown by gauges. Such mechanism is ideal, but would certainly be rather costly. Its great value was that it informed us with certainty what proportions of ether in the atmosphere were necessary to induce and maintain anæsthesia (_see_ Appendix II.). A simple mechanism was brought out shortly afterwards by Dr Shipway, of Guy’s, and is known as Shipway’s warmed Ether. It consists essentially of the following parts (_see_ Fig. 29):-- (1) A small hand bellows (B). (2) An ether bottle, with tube for delivery of air stream dipping deeply into the fluid: the exit tube of course does not dip in. The bottle stands in a metal pan in which water at about 75° Fahr. is to be placed (E). (3) A thermos flask (W) in which is a metal tube (U). The etherised air passes along this tube, and picks up heat from its walls. The thermos is filled with water at about 180° Fahr. [Illustration: FIG. 29.--Shipway’s warmed ether vapour apparatus.] (4) A mask upon which a towel or gauze is to be stretched: the rubber tube bringing the air and ether is brought through the covering material and delivers the anæsthetic vapour in the region of the mouth. (5) Additional to the above, there may be added a small chloroform bottle (C). In specimens of the instrument containing this convenience, there has, of course, to be a regulating tap (T) at the head of the ether bottle, which will divert more or less of the air stream towards the chloroform. This little machine, somewhat resembling a cruet stand in its appearance was widely used in France. Owing to the kindness of the Edinburgh Red Cross Committee, one was provided for the Base Hospital with which the author proceeded to Salonika, where he used it extensively. The impression of it formed by himself and others was that it was peculiarly easy to maintain with it a steady level of anæsthesia. It had, however, no claim to banish post-anæsthetic bronchitis and pneumonia, of which in spite of much anxious care and thought, a fair number of cases were seen during the winter time (_see_ page 151). In using the machine, it is necessary to remember that from the physical point of view, one is providing from the machine a small part only of the total volume of air required by the patient. The bellows are quite small: one squeeze of the hand will not supply more than about the equivalent in volume of one or two fluid ounces. The larger part of the volume required by the patient has to be obtained from the general atmosphere, so that the percentage of ether which may be as high as 25 in the exit tube, will be greatly lowered by the time it reaches the patient’s respiratory tract.