Page:The American Cyclopædia (1879) Volume IV.djvu/515

CHLOROFORM CHLORO-METHYL 503 bodies; but the only practicable method for its production on a large scale consists in the distillation of alcohol from chloride of liine. Six parts of chloride of lime, 24 parts of water, and one part of alcohol are mixed in a capa- cious still, and the temperature raised as rapid- ly as possible till it reaches 180 F. The dis- tillation is then continued until about one part and a half has passed over ; the products, con- sisting chiefly of chloroform, accompanied by water, collect in two layers in the receiver, the chloroform constituting the lower layer. It is decanted from the aqueous portion, and agitated with oil of vitriol in order to destroy traces of volatile oils which accompany it ; by another rectification it is obtained in a state of purity. Chloroform is a colorless, volatile liquid, of high refracting power. It has a powerful and agreeable ethereal odor, and a sweet, penetra- ting taste. Alcohol and ether dissolve it in every proportion, but it is very sparingly solu- ble in water. Concentrated sulphuric acid has no action upon it, and even potassium does not occasion its decomposition. It is inflamed with difficulty, and burns with a greenish, somewhat smoky flame, producing hydrochlo- ric acid as well as carbonic anhydride and wa- ter. By admixture with an alcoholic solution of potash it is decomposed, potassic chloride and formiate being produced. Chloroform free- ly dissolves sulphur, phosphorus, iodine, cam- phor, resins, gutta percha, caoutchouc, strych- nia, morphia, quinia, and fatty bodies. The spe- cific gravity of the liquid is 1'497, of its vapor 4'2; boiling point 142 F. ; it remains liquid at F., but can be solidified by sudden evaporation. Chloroform vapor passed over red-hot copper is partially converted into acetylene. Pure chlo- roform is decomposed by exposure to light and air; but in the dark it remains unaltered in a vessel only half filled with it. The vapor of chloroform possesses the remarkable power of producing in the person who has respired it complete temporary insensibility to pain. It may be readily inhaled for this purpose by placing a small quantity of the liquid upon a sponge or a handkerchief, which is to be held before the mouth and nostrils ; and it is now commonly employed for rendering patients in- sensible to pain during severe surgical opera- tions. It is of great importance that the chlo- roform used for this purpose should be quite pure. In some cases it has been found after exposure to a strong light to have undergone spontaneous decomposition. It ought to com- municate no color to oil of vitriol when agi- tated with it. The liquid itself should be free from color, and it should be perfectly destitute of any chlorous odor. When a few drops are allowed to evaporate on the hand no unpleasant odor should be left. At present chloroform is much more largely used than ether for the production by inhalation of surgical anaesthe- sia. It is generally admitted to have over ether the advantages of rapidity of action, conve- nience of administration, agreeableness of odor, and less subsequent nausea. These advantages, however, in the opinion of many physicians in various parts of the world, and especially of nearly all the physicians of Boston, Mass., and of Lyons, in France, are more than counter- balanced by the fact that chloroform is danger- ous to life. A marked change of opinion, in favor of ether as against chloroform, has re- cently taken place in England. A large num- ber of deaths from the inhalation of chloro- form have occurred in the hands of the most skilful and experienced physicians. It is true that the number of deaths so produced bears a very small proportion to the total number of administrations, yet it should be remem- bered that only an extremely small number of deaths have ever been ascribed to the in- halation of sulphuric ether, and those per- haps incorrectly, and that the latter agent is equally efficient at the cost of a trifling inconvenience and a few seconds more time. Deaths from chloroform take place in three ways : 1, gradual asphyxia, for which the remedy is removal of the drug and fresh air ; 2, sudden apnea or cessation of respiration, fol- lowed by asphyxia, for which the remedy is artificial respiration and the galvanic battery ; 3, syncope from heart-shock, for which there is probably no remedy. Besides its use as a surgical anaesthetic, the inhalation of chloro- form has been employed in midwifery, and to relieve intense pain, and to control convulsions, especially those produced by tetanus and strych- nia. There is no record of death from its em- ployment in obstetric practice in skilled hands, although there seems to be no good reason for its being safer in this department of practice than in others. Inhaled in the quantity of a few drops and largely diluted with atmospheric air, so as not to produce anaesthesia, it is used to relieve cough and irritability of the air pas- sages. It may be administered by the stomach, combined with ether, sirup, mucilage, or glyce- rine, for the relief of nausea, seasickness, and nervous irritability. The writer has seen two ounces of chloroform, swallowed with suicidal intent, prove fatal in less than an hour. Ap- plied externally, it is an irritant. Dr. Augus- tus Waller has shown that the admixture of chloroform greatly promotes the rapidity with which belladonna and probably other sub- stances are absorbed by the skin. Chloroform is also used as a solvent in the preparation and purification of alkaloids and other sub- stances for pharmaceutical and analytical pur- poses. (See ANAESTHETICS.) CHLORO-METHYL, or Bichloride of Methylene, a substance produced by exposing to sunshine, in a glass globe, chlorine and gaseous chloride of methyl. The products of the decomposition, which consist, in addition to the chloro-methyl, chiefly of chloroform, are collected in bottles, artificially cooled and connected with the gen- erating globe. The chloride of methyl may be made for the purpose by heating together one part of wood spirit, two parts of common salt,