Chloroform, or the Terchloride of For-myle. C3 H, Cl3. A dense, limpid, colourless liquid; readily evaporating, and possessing an agreeable, fragrant, fruit-like odour, and a saccharine, pleasant taste. Sp. Gr. 1.48 to 1.496. Slightly soluble in Water, but mixing with Ether and Alcohol in all proportions. It is a compound of 2 atoms of Carbon, 1 of Hydrogen, and 3 of Chlorine.

Med. Prop. and Action. Inhaled in the form of vapour, anaesthetic; taken internally, narcotic and anti-spasmodic: applied externally, undiluted, counter-irritant; diluted, anodyne.

Offic. Prep. 1. Linimentum Chloroformi (Chloroform fl. oz. ij.; Liniment of Camphor fl. oz ij.).

2. Spiritus Chloroformi (Spirit Of Chloroform, Or Chloric Ether) (Chloroform Fl

oz. j., Rectified Spirit fl. oz. xix.). Sp. Gr. 0871. This preparation is intended to supersede that known before the publication of the Brit. Pharm. as Chloric Ether, which was of uncertain strength. It is the best form in which Chloroform can be administered internally, and is a most valuable anodyne, stimulant, and anti-spasmodic. Dose, ex. - exxx., or more.

* Med. Gazette, May 24, 1850.

Brit. and For. Med Chir. Rev., Jan. 1861.

Dose of Chloroform for internal administration, ej. - ex. rubbed up with syrup or yolk of egg and mucilage; for inhalation, exv. - fi. drm. j. repeated as required.

Chloroform is one of the principal ingredients in the popular anodyne and narcotic medicine called Chlorodyne. According to Mr. Squire,* the following is the probable composition of Chlorodyne: - Chloroform oz. iv.; Rectified Spirit oz. iv.; Treacle oz. iv.; Extract of Liquorice oz. iiss.; Muriate of Morphia grs. viij.; Oil of Peppermint exvi.; Syrup 17 1/2 oz; Prussic Acid (2 per cent.) oz. ij. Dose, ev. - ex.

Chloroform was first discovered and described by Soubeiran, in 1831, and by Liebig, in 1832; and its composition was first accurately ascertained by Dumas, in 1835. None of these chemists, however, appear to have been aware of its anaesthetic properties; the honour of this great discovery is due to Prof. Simpson, of Edinburgh, in 1847. It certainly deserves to rank as the most important improvement in modern medicine or surgery: a few drops inhaled producing such complete insensibility, that the most painful operations of surgery can be performed without consciousness or pain on the part of the patient. Sulphuric Ether, originally discovered in America to be a powerful anaesthetic agent, was exciting the attention, not only of the profession, but of the public, when Chloroform was introduced by Dr. Simpson, and was almost immediately substituted in its place. The advantages of Chloroform over Ether were found to be as follows: - 1. The effect was more complete and direct; 2. The quantity required was smaller; 3. The odour was more agreeable and less irritating; 4. The effect produced was more permanent; 5. Recovery took place decidedly quicker than when Ether was employed. The relative advantages of Ether and Chloroform have lately been re-investigated by the Committee on Chloroform appointed by the Medico-Chirurgical Society, In their Report they state that Ether is slow and uncertain in its action, though it is capable of producing the requisite insensibility, and is less dangerous in its operation than Chloroform. In many respects its action is similar to that of dilute Chloroform. The primary stimulating effect of Ether on the heart's action is greater and of longer duration, and the subsequent depression of the heart's action is not so great as that produced, at the same degree of insensibility, by Chloroform. On the whole, however, the Committee concur in the general opinion which in Great Britain has led to the disuse of Ether as an inconvenient anaesthetic. They find a mixture of Ether and Chloroform to be as effective as pure Chloroform, and a safer agent when deep and prolonged anaesthesia is to be induced; though slow in its action, it is sufficiently rapid in its operation to be convenient for general use. They suggest for use a mixture composed of Ether three parts, Chloroform two parts, Alcohol one part (by measure), on the grounds that Ether and Chloroform blend uniformly when combined with Alcohol, and the constituents escape equably in vapour. (See AnAesthetics, part ii.)

831. Chloroform, when first inhaled, gives rise to exceedingly pleasant sensations, and a rapid flow of thoughts and images, resembling an agreeable dream, until, as the dose is increased, these become contused and incoherent. Dr. Snow has divided its operation into five degrees or stages.

The First Degree includes the slighter effects which are experienced by the patient, whilst he retains sufficient consciousness to appreciate his situation, and a knowledge of what is occurring around him.

The Second Degree is a dreaming or wandering state of mind, which is observed when the patient is silent, immediately preceding the loss of consciousness.

* Companion to the Brit. Pharmacopoeia, p. 58.

Lancet, July 9, 1864.

The Third Degree. In this there are no voluntary movements, articulate sounds, nor anything indicating the presence* of ideas; but there may be involuntary muscular contractions or rigidity.

The Fourth Degree is a state of absolute relaxation of the voluntary muscles, in which no contraction can be excited in them. The breathing is sometimes stertorous in this stage.

The Fifth Degree is a state of impeded respiration observed previous to death in animals killed by Chloroform.

These various degrees run gradually into each other, and cannot always be clearly distinguished; it is seldom necessary, however, to carry the narcotism beyond the third degree, even in the most severe operations. The pulse in rally somewhat accelerated during the inhalation.