This section is from the book "A Practitioner's Handbook Of Materia Medica And Therapeutics", by Thos. S. Blair. Also available from Amazon: A Practitioner's handbook of Materia Medica and Therapeutics.
Camphora. This substance is classified as stimulant, diaphoretic, sedative, expectorant, carminative, antiseptic, analgesic, and antipruritic. If this is all true, it is a wonderful remedy. It is used in an empirical manner, and it needs study. It is altogether too freely combined with other remedies, which it seems to modify in a manner not well understood. It must be borne in mind that camphor has toxic influences, causing cyanosis, delirium, vomiting. convulsions, and other symptoms of irritation of the brain. In large doses there is much difference of opinion as to its range of utility. The fact is that camphor established its fame in the treatment of cholera. This is a condition in which a remedy would be slowly absorbed, and in which the functions of the nervous system are so depressed as to require an irritant to arouse them. To my mind this suggests that quite large doses of camphor might rationally be employed in states of collapse and in the stupor and exhaustion of adynamic fevers; but where the nervous reactions are normal and absorption is active, it impresses me that large doses have no place. In small doses camphor is given in a host of affections, the indications of which are better met by other remedies.
* Caffeine, 20 gr.; Salicylate of Soda, 17 1/2 gr.; Water, 80 m.
Limiting the indications to those well borne out in professional experience, we find that the successful use of camphor is to influence the nervous system either in large or in small doses.
It succeeds in hvsteria because it is a nerve sedative; in nervous headache, since it is due to prolonged mental strain as a rule, and camphor is a nerve sedative that improves the nerve tone like cactus does the heart; in the first stages of a cold, because that stage of a cold is really a vaso-motor disturbance; in bronchitis, asthma, and whooping cough, because it is a sedative influencing the muscles as an antispasmodic in small doses, but causing tonic spasm in large, toxic doses; nervous vomiting and palpitation, because it is a sedative to nervous reflex action. Give in I to 5 I. doses of Spiritus camphora, or I to 5 gr. of Camphora monobromata. This latter preparation adds hypnotic influences to that of camphor, and is very valuable in nervous irritation from reflex causes. Carbolate of camphor is made by mixing together and straining, after twenty-four hours standing, I part by weight of carbolic acid and 3 parts of camphor. It is a superb antiseptic, but must not be mixed with water or glycerine. Use pure or in any proportion mixed with cotton seed oil or petroleum derivatives.