The source of ichthyol is a bituminous mineral rich in the remains of fossilized fish and other marine animals. From this mineral it is derived by distillation, and is subsequently treated with sulphuric acid, yielding a sulphonate. Neutralized by ammonium and sodium, corresponding ammonium and sodium ichthyol salts are obtained.

Ichthyol is rich in sulphur, containing about 10 per cent—and this is chemically combined with the other ingredients, and partly with oxygen and partly with carbon. It is an oily substance, with a bituminous odor and taste, a reddish-brown color, and is freely soluble in water and in a mixture of equal parts of alcohol and ether, and also mixes well with lonolin, vaselin, and fats and oils generally. It is the ammonium salt of ichthyol that answers to the foregoing description. Thiol is for the most part preferred to ichthyol. They are isomeric, but thiol is purer in form, less irritating, and has no toxic properties. The facts stated of ichthyol are equally true of thiol, with the important exception that thiol is much more pleasant for administration, and may be given more freely without risk

Actions and Uses

Notwithstanding its odor and taste, ichthyol is well borne by the stomach, and promotes appetite and digestion. It increases assimilation and hinders retrograde metamorphosis, whereby the nutrition is improved and the body-weight brought up to the normal level. According to Dr. Cranstoun Charles, massive doses of ichthyol caused in animals only diarrhoea. The same results were arrived at by Prof. Baumann and Dr. Schotten. Dr. Helmers, in Zuntz's laboratory, found that in experiments on himself it was without any injurious effect, but promoted the metabolism in which sulphur is concerned, and the amount of this substance which had accumulated required seven days in which to become eliminated. It has a decided antiseptic action, and is fatal to pathogenic organisms. It increases the volume and force of the circulation after stimulating the primary assimilation.

As a compound rich in sulphur, it is adapted to the treatment of those morbid states in which this substance has proved efficacious. According to Unna, of Hamburg, it is serviceable in cases of acne, furuncle, lepra, sycosis, and other cutaneous diseases. Similarly, it is effective in erysipelas, erythema, eczema, and analogous affections. Unna finds that it diminishes heat, reduces swelling, and relieves pain. In the treatment of skin diseases he employs the remedy internally as well as topically. The dose for internal administration in such cases ranges from 5 to 10 grains two or three times a day. It is usually dissolved in water for this purpose. Of equal parts of ichthyol and water, 5 to 20 drops three times a day are usually given. For application to eruptions, the proportion of ichthyol ranges from 1 to 10 parts. It is mixed with water, glycerin, vaselin, and lanolin, in varying proportions, according to the effects desired, or it is combined with zinc-ointment, soft soap, and other unguents. The following are among the more useful combinations: Rx Ichthyol, lanolin, vaselin, equal parts. M. Rx Ichthyol, 4 parts; sulphur, precipitated, 4 parts; wheat starch, 20 parts; zinc oxide, 20 parts; vaselin, 40 parts. M. A paste for the face. In the treatment of gastro-intestinal catarrh it may be given as follows: Rx Ichthyol, 30 to 60 parts; oil of peppermint, 1 part; absolute alcohol, 10 parts; distilled water, 1,000 parts.

Good results are claimed for ichthyol in the treatment of phthisis, chronic rheumatism, chronic alcoholism, and chronic wasting diseases. Cohn maintains its superiority over guaiacol as a remedy for phthisis. The explanation of its utility in wasting diseases is afforded by the remarkable influence over the retrograde metamorphosis of certain constituents of the body, and in its effects in retarding the disintegration of the albumins and in favoring their accumulation and formation. As Zuelzer and others have shown, it has a remarkable power to check waste, the urinary solids and the nitrogenous excreta being greatly diminished. Hence it is under its administration the body weight increases, the income is promoted and the outgo lessened, and these important results are accomplished without in any way impairing digestion or irritating the gastro-intestinal mucous membrane. In rheumatic affections, applications to the affected joints are combined with the internal administration of the same. Remarkable results are claimed for this agent in the treatment of gonorrhoea. A warm solution of one half to one per cent of ichthyol has been used quite successfully; with this the canal may be thoroughly irrigated.