Glass bottle labelled 'Camphor'. Camphor is a waxy, white or transparent solid with a strong, aromatic odor. It is a terpenoid with the chemical formula C10H16O. It is found in wood of the camphor laurel (Cinnamomum camphora), a large evergreen tree found in Asia. Savory, 'A companion to the Medicine Chest', 1836, p. 18-19 says:
“Camphor. – Is used by many practitioners in low fevers, and in nervous and spasmodic diseases, but with doubtful effect. In small doses, for instance, of from one to three grains, it acts as a sedative and diaphoretic. (…) It is also a useful adjunct to bark, in typhus fever; to valerian, asafoetida, volatile alkali, and ethereals, in hysteric and nervous complaints, and to antimonials and other diaphoretics, in rheumatism and certain inflammatory disorders. In cases of febrile action, where the object is to allay irritation, promote perspiration, and induce sleep…(..) Camphor is also employed externally in rheumatic and other painful affections of the muscles, joints, &c. (…)”
Nowadays, there are still anti-itch gels and cooling gels with camphor as the active ingredient. Camphor is an active ingredient (along with menthol) in vapor-steam products too, such as Vicks VapoRub.