Advantages and Disadvantages of Chloroform. The light portable appliances which are alone necessary for chloroform anæsthesia, the comparative cheapness of the method, and the _apparent_ ease with which its administration may be conducted, are all great temptations to its use. Those who feel the temptation strong upon them are advised to remember the following quotation from the writings of Professor Leonard Hill:-- “Chloroform is a drug used by the young anæsthetist with the utmost hardihood, and until he has had the misfortune in his practice to meet with a death caused by it, he derides the danger of the drug, and asserts that its safety merely depends on the care and skill of the administrator. After losing his patient, he falls to descanting on the unavoidable dangers of the drug, dangers which he is now the first to maintain cannot be met by any degree of skill in administration.” The most distressing and probably the most common chloroform fatalities are exemplified in administration given for the most trifling conditions, such as opening abscesses or extracting teeth. In general, we use chloroform if for any reason ether is not applicable. For examples of cases of this description, the reader is referred to the chapter upon the choice of anæsthetics. CHAPTER XII. ETHYL CHLORIDE. Chemically this drug has the formula C_{2}H_{5}Cl. It is a colourless fluid so volatile that it boils at ordinary room temperature. Its vapour is highly explosive, and the fluid itself very inflammable. The drug is supplied by the makers in small tubes with a metal end which can be opened by pressing a little lever (_see_ Fig. 40), varying in type with the brands made by various makers. Two brands are sold by each firm; one is chemically pure, intended for use as a general anæsthetic; the other is not so pure, and is only sold for local anæsthesia. Such a product is not suitable for inhalation. [Illustration: FIG. 40.--Tube of Ethyl Chloride.] Physiology. The special points in the physiology of ethyl chloride may be briefly summarised as follows:-- 1. After a trifling preliminary rise, the effect of the drug is to lower the blood pressure appreciably. In the human adult subject, this fall becomes appreciable when more than 3 c.c. have been given; if the dose exceed 5 c.c. a fall of 30 to 40 mm. of Hg. is probable,--occurring as it does within a period of perhaps twenty or thirty seconds, such a fall cannot be regarded as safe. 2. The cause of this fall is diminished cardiac output from weakening of heart muscle. The vagus though not paralysed, does not appear to be unduly irritable, as it does with chloroform.