It is scarcely necessary to repeat that camphor should not be given during the existence of active vascular irritation, congestion, or inflammation of the brain, nor in high febrile excitement with a strong pulse and sthenic state of system; and that, in any case presenting these conditions, whatever otherwise may be the indication for its use, they should be subdued before it can with propriety be prescribed. Nor should it be administered when the stomach is inflamed.

Local Use of Camphor. Few medicines are more frequently employed topically than camphor. In the form of vapour, it is sometimes inhaled in asthma, spasmodic coughs, and chronic catarrhal affections; and there is no doubt that its constitutional impression may be obtained in the same way. It may be applied by means of an ordinary inhaler, placed in water more or less heated to favour the volatilization of the camphor. M. Raspail recommends that a small tube, a quill for example, should be filled with the coarsely powdered medicine, and loosely closed at each end so as to admit the passage of air, and that this should be used in the same manner as a cigar, but without burning. In the inhalation of camphor, care must be taken to arrest the process, when signs are exhibited of its acting on the brain.

Another mode of using the vapours of camphor is in the form of a vapour hath. For this purpose the patient may be seated naked on a stool, and covered with a blanket closely applied about his neck, and hanging down around him upon the floor. A plate of heated metal, holding half an ounce of camphor, should then be placed underneath the blanket, so that the vapours may completely surround the body. A similar arrangement may be made, by means of crossed hoops and the bedclothes, about the patient in bed, if unable to rise. The vapour thus applied is highly recommended by M. Dupasquier, in Chronic rheumatism.

A piece of camphor held before the nostrils, so that its vapour may be snuffed up into the nasal passages, is sometimes beneficial in coryza. Powdered camphor has been recommended to be used in the same way, and for the same purpose, as well as for the relief of various spasmodic and catarrhal affections of the air-passages.

Dissolved in different liquids, camphor is injected into the urethra, vagina, and rectum, for the purpose of relieving irritations of those passages, and is very much used as an application to the surface, chiefly with a view to its anodyne effect, in various painful affections, as gout, rheumatism, neuralgic pains, sprains, bruises, chilblains, etc. It is also used as a stimulant to gangrenous, flabby, and indolent ulcers.

In the solid state, also, camphor is sometimes employed externally. Allusion has already been made to the use of the powder in the form of snuff, for which purpose it should be made very fine. In a similar state, it may be applied in cataplasms to painful parts; and half a drachm of it, thus applied to the perineum, will sometimes relieve the chordee attendant on gonorrhoea.