_D._--Open ether. Alternative method of holding mask. The towel and gauze have been removed so as to show the tilting of the mask which this method is liable to cause.] To Mr Bellamy Gardner’s outfit, the author adds a folded towel, pinned at one corner, so as to form a short cone. The base of this cone embraces the mask and face; through its upper apperture the anæsthetic is dropped on to the mask. The cone can be rotated into the position most convenient for this purpose in any given position of the patient’s head (Fig. 28). Problems of the Induction Period. Open-ether is not a powerful anæsthetic, just not powerful enough for one to be sure that one can induce full anæsthesia with it alone, in a powerful subject. The reason for this is shown in Appendix II, and may be here condensed by explaining that some 18 per cent. to 20 per cent. of ether vapour is required to induce anæsthesia, while it is not easy to get more than 14 per cent. off an open mask. How is this situation to be met? Reference has already been made to one solution of the problem. _A closed ether method may be used for induction_, and this practice is widely used. The author does not often adopt this course, fearing that the undesirable features of closed ether may persist even after the change to an open method has been made. Another possibility even more widely favoured is to use _chloroform as the inducing agent_, and only to turn to ether when full anæsthesia is obtained. To this plan the author is strongly opposed. It exposes the patient to the risks of the induction stage of chloroform which are much greater than those of the later stages. Moreover, to develop the full advantages of open-ether, a preliminary hypodermic of morphia is essential, and the drawbacks of chloroform _plus_ morphia are elsewhere mentioned (page 43). The use of a _mixture of chloroform two parts, ether three parts_, presents the same disadvantage, but in a degree so much smaller that in powerful or alcoholic patients, the author believes this to be the method of choice (_see_ Chapter xiv.). _Dr Silk_ has recently suggested another plan. He has sought to make open-ether easy for the non-expert with a view of encouraging the wider use of so valuable a method. For this purpose he advocates the admixture of one part of chloroform in thirty-two of ether (a dram of chloroform in four ounces of ether). This is to be given in exactly the same way as perhalational ether, and will, Silk says, give a type of anæsthesia, and a degree of safety, identical with those of pure ether. The author’s experience with Silk’s mixture is too limited to enable him to offer any opinion upon its merits.