According to Fronmüller, naphtalin (or naphthalin) was discovered so long ago as 1820, but its applications in medical practice have been developed since the subjects of antiseptics and bacteriology have assumed so important a place in modern pathology and therapeutics. It is now obtained in quantity from a by-product of gas-manufacture, and after purification appears in commerce in the form of rather brilliant, rhombic crystals, having a somewhat aromatic but acrid, burning taste. It is not soluble in water, but dissolves in ether and acetic acid.

The best form for the administration of naphtalin internally is the compressed pellet, and this form secures the preservation of the drug as well as facilitates the administration. Naphtalin may be combined with any aromatic powder—for example, the official pulvis aromaticus compositus, powdered nutmeg, or cinnamon—and given as a powder. The dose ranges from one quarter of a grain to five grains.

Naphtalin does not distress the stomach nor cause nausea, the present experience being that it is rather a stomachic tonic. It is supposed that it passes unchanged from the stomach into the intestine, where it acts as an antiseptic. The proof of this action is afforded by the complete deodorization of the stools. To remove the fecal odor from a mass of faeces implies the possession of great powers, and is conclusive as to changes occurring in the naphtalin itself. It follows that the fermentative processes producing more or less of the offensive compounds of sulphur, phosphorus, and carbon, must be arrested by naphtalin.

Although insoluble in water, this remedy diffuses through the body, and ultimately escapes in part from the lungs and kidneys, but largely in the faeces. It has some mysterious influence on the function of nutrition, or on the trophic nervous system, for, when given to dogs freely, cataracts form. No such result can be expected from its medicinal use in man; but a judicious practitioner will hardly risk such a result by large doses, protracted administration, and careless observation.

The therapeutical applications are based on the studies that have been made of its physiological actions; they are both internal and external. Dupasquier advises the following solution for the stomachal administration: Naphtalin, Э j; dissolve in boiling alcohol and add sufficient simple sirup to make up to eight ounces. A tablespoonful can be taken three or four times a day. This formula is said to be an excellent expectorant, and to remove the fetid character of the pus in some cases, of bronchorrhoea. The most important of the internal uses of naphtalin is in the treatment of diarrhoea, dysentery, round worms, and typhoid. Rossbach has found it very useful in the first two, and the author has had excellent results in some cases of chronic dysentery. Also, it has appeared to the author to be of great relative utility in the cases of diarrhoea due to obstruction of the portal circulation. In chronic dysentery and diarrhoea, acute and chronic, it has proved very successful in the practice of Dolgopoloff.

Naphtalin has an effect on the genito-urinary tract, in passing through in the urine, which is of no little service in catarrhal states of the mucous membrane, in pyelitis, cystitis, etc. Offensive urine is sweetened by it, and hence an impression is made on the catarrhal process. On the other hand, Prof. Rossbach asserts that in certain subjects its administration for other purposes may excite a violent cystitis with strangury, and that it must be administered with caution when the kidneys are damaged.

The external uses of naphtalin consist in applications to ulcers (syphilitic, varicose of the leg, or other unhealthy and sloughing forms), in leucorrhoea of a fetid character, in gonorrhoea and cognate affections. Fronmüller asserts that he has had "marvelous results" in some cases of bed-sores caused by prolonged decubitus. The same authority affirms its superiority to iodoform in these diseases.

In eczema, pityriasis, psoriasis, etc., it is often highly beneficial. An ointment with vaseline (1 to 3) is recommended when there is intelligent supervision.