Formula

Chc13. Sp. gr. 1.491.

Derivation

Chloroform is obtained by the distillation of alcohol with chlorinated lime, or by the action of chlorine upon alcohol. It is a colorless, limpid, neutral, and volatile fluid, with 22 a hot, aromatic, sweetish taste, and a peculiar fragrant odor. It is readily soluble in alcohol and in ether, and, if pure, it sinks into water as transparent globules free of milkiness. It is antiseptic, and will not coagulate albumen. It should be kept in a dark, cool place. If exposed to the light for any length of time, chloroform becomes unfit for use as it develops chlorine, hydrochloric acid, and carbonyle chloride. The presence of acid in chloroform will turn blue litmus paper red, and if chlorine is present it will form a white precipitate with nitrate of silver. If impure from improper manufacture, an oily odor will remain on the hand after evaporation. Chloroform fit for use (Chlorofor-mum Purificatuni) should have a specific gravity of from 1.491 to 1.525, absolutely transparent and colorless, neutral to test paper, non-irritating when inhaled, and should evaporate entirely, leaving no residue or smell on a glass surface. Chloroform purified by crystallization is considered to be the best form for purity. The boiling point is 1420 F.

Medical Properties And Physiological Action

Chloroform, when inhaled, is an anaesthetic; and when administered internally, is anodyne and antispasmodic. Its effects on the system are similar to those of ether, but more powerful and more rapidly produced, and it requires more care in its administration, both internally and by inhalation of the vapor. When inhaled, the vapor of chloroform causes a sensation of warmth in the mouth and throat, a sense of relaxation, and finally unconsciousness. Respiration is at first full and deep, but soon becomes more rapid and shallow. The pulse becomes at first somewhat fuller and stronger for a short time, and then fails in strength, and is more rapid. Total muscular relaxation is dangerous. The effect on the air passages is slight irritation, with no primary arrest of the respiration, as is the case with ether. The pupils at first slightly dilate, but afterwards contract: but if they dilate after such contraction the case becomes dangerous, and death may suddenly ensue. In some patients, the first effects of the chloroform are violent struggles, and, in such cases, it is dangerous to continue the inhalation rapidly. Drunkards and athletes are prone to be thus affected. When taken internally it causes a feeling of warmth in the stomach, followed by coldness, similar to ether, and if taken in large quantity, undiluted, it acts as an irritant poison, inducing violent gastritis. It is diffused into the blood, and affects remote parts. It increases the action of the circulatory system, producing excitement of the brain, followed by a deep, heavy sleep; and in poisonous doses, stupor and insensibility.

The first effect of chloroform is upon the brain, then upon the sensory portion of the spinal cord, then the motor part of the cord, then the sensory parts of the medulla oblongata, then its motor portion, thereby causing death through the failure of the vaso-motor and respiratory centres, unless heart failure has already taken place, which is not usually the case.

When locally applied, chloroform acts as an irritant and anaesthetic on the sensory and motor nerves, but when inhaled has little or no effect on these nerve trunks. Recent investigations have shown that "the primary action of chloroform on the vital functions of circulation and respiration is greatly to depress the vaso-motor system, thereby causing an extraordinary fall of blood-pressure. Some cardiac enfeeblement and dilatation adds to the fall of pressure." Chloroform has little or no effect upon the blood when it is inhaled, but lowers the bodily temperature by assisting in the dissipation of heat, and its action on the nervous production of heat. Owing to its great volatility, chloroform is rapidly eliminated by the kidneys and lungs.

Locally applied to the skin, it causes redness and burning and if confined so that evaporation is prevented, will induce vessica-tion. It is somewhat anaesthetic when locally applied, but is also a powerful irritant. The vapor of chloroform when inhaled produces symptoms similar to those of ether, except that the sensations of choking are absent, and the stage of excitement is of shorter duration and less violent.

Sabarth has divided chloroform-narcosis into three stages: In the first, the symptoms are similar to alcoholic intoxication. The second stage is that of anaesthesia, consciousness and sensibility are abolished, the muscles are relaxed, and perfect quiet ensues. This is the surgical stage.

The third stage is one of profound narcosis, with stertorous breathing, intense muscular relaxation, abolition of the ordinary reflexes, and fall of bodily temperature. This is a dangerous stage, and its induction is not justifiable, except under very peculiar circumstances.

The following are some of the practical conclusions of the second Hyderabad Commission: "The recumbent position on the back and absolute freedom of respiration are essential. If during an operation this position cannot be from any cause maintained during the administration of chloroform, the utmost attention to the respiration is necessary to prevent asphyxia or an over-dose. If there is any doubt about the state of respiration, the patient should be at once restored to the recumbent position on the back. To insure absolute freedom of respiration, tight clothing of every kind, either on the neck, chest, or abdomen, is to be strictly avoided; and no assistants or bystanders should be allowed to exert pressure on any part of the patient's thorax or abdomen, even though the patient be struggling violently. If struggling does occur, it is always possible to hold the patient down by the shoulders, pelvis, or legs, without doing anything that can possibly interfere with the free movements of respiration. An apparatus is not essential, and should not be used, as, being made to fit the face, it must tend to produce a certain amount of asphyxia, and take up part of the attention required elsewhere. However it is made, it introduces an element of danger into the administration. A convenient form of inhaler is an open cone or cap with a little absorbent cotton inside at the apex. At the commencement of inhalation care should be taken by not holding the cap very close over the mouth and nose, to avoid exciting, struggling or holding the breath. If struggling or holding the breath does occur, great care is necessary to avoid an over-dose during the deep inspirations which follow. When quiet breathing ensues, as the patient begins to go over, there is no reason why the inhaler should not be applied close to the face; and all that is then necessary is to watch the cornea and see that the respiration is not interfered with.