Camphor may be used in pill or emulsion, but the latter form is greatly to be preferred; as, in the former, it is more apt to irritate the stomach, probably by floating upon the gastric liquids, and thus coming in a concentrated state into contact with the mucous coat.' The emulsion may be made by first pulverizing the camphor with a few drops of alcohol, and then robbing it up with powdered gum arabic, loaf-sugar, and water, to which a little myrrh may be added, in order to favour the suspension of the camphor. Another mode of preparing the emulsion is first to dissolve the camphor in a little chloroform (see Chloroform), and then to incorporate the solution, by means of the yolk of an egg, with water. The medicine may also be given suspended in milk; but an objection to this is its liability to undergo change in a short time. The officinal aqueous solution, and the tincture, are convenient forms for administration.

The dose of camphor varies from one to twenty grains. As a simple nervous stimulant, it may be given in the dose of from one to three grains, repeated every hour or two, if required. For its full effect as a cerebral stimulant, or indirect sedative, the medium dose is from five to fifteen grains. When a powerful effect is required, as in certain painful neuralgic or spasmodic affections, the dose may be increased to a scrapie. By enema, it may be given in twice or three times these quantities.

The following preparations of camphor are officinal.