The name applied to this agent harmonizes with such as phenol, naphthol, and others, now in general use. It is a salicylate of phenol. As it appears in commerce it is a white powder, having a crystalline structure. It is entirely insoluble in water, and hence, when first used by Georgi in the form of powder, its antiseptic powers remained undetermined. It is made by combining salicylic and carbolic acids—sixty of the former and forty of the latter by weight. The insolubility of salol in water explains its lack of taste. It is asserted that it is equally insoluble in the gastric juice, but dissolves freely in the intestinal juices after the pancreatic has joined. More recent observations throw doubt on this assumption, and show rather that the separation into its constituents begins in the stomach. If, however, the greater part of the carbolic acid remains in the combination until the small intestine is reached, no irritant effects occur in the stomach, and at the moment it is freed it possesses the maximum antiseptic power (Nenki and Sahli). Dose, gr. v— 3 j.

Properties

Actions and Uses.—Salol can be administered in the form of compressed pellet, of powder, pill, or wafer, etc., and as it continues intact during its stay in the stomach, can be so timed in its administration as to act on the intestinal mucous membrane only, or at any stage of the process of intestinal digestion. Salol is the most advantageous if not the most powerful germicide. The temperature of the body has been reduced by it from 104° Fahr. to 98° (Nenki, Lepine, etc.). In common with all the antipyretics, the decline in the body-heat is coincident with sweats, more or less profuse, but not the exhausting sweats accompanied with profound depression of the vital powers—the collapse, even—which are caused by many of the same group. Furthermore, salol differs from many of the antiseptic antipyretics in that the rise of fever after the period of apyrexia is not signalized by a chill, a rigor, or a pernicious cold stage. In general it may be asserted that salol is free from any toxic action, although it may be shown hereafter that there are certain subjects affected in a very unfavorable manner by it. Although idiosyncrasy is by its nature exceptional, it should not be forgotten that the symptoms present under these circumstances are but exaggerations of natural conditions, and are present, probably, in all cases, yet, for the most part, are not recognizable because too minute and ill-defined.

We owe the discovery of the analgesic property of the chinoline derivatives to Lepine, to See, and several Russian observers (Todorsky). Therapeutically, the anodyne property of salol is exhibited in the cases that are rheumatic in source. It has also been shown to lower the reflex function of the spinal cord, and thus to abate spasm.

After the decomposition of salol in the intestine a chemical change wrought by the pancreatic juice—its component elements are no doubt disposed of in accordance with their individual affinities.

Under the continued administration of salol, the urine changes in appearance just as it does when carbolic acid is the agent undergoing elimination. We can not conceive the possibility of Nenki's assertion being true that the carbolic acid when set free in the intestine forms combinations that do not enter the blood. When the quantity of carbolic acid absorbed is large, the urine becomes darker, and finally almost black in color. The test for carbolic acid and salol is the same—i. e., a solution of perchloride of iron, which strikes a fine violet color on being added to urine containing them. Hence it is proved that carbolic acid has passed from the intestine through the kidneys into the urine. The intermediate combinations formed are not well known, but it is probable, of course, that when liberated in the small intestine it must pursue the course its chemical relations require, as we have before stated.

The dose of salol varies with the circumstances--the maximum, when its antipyretic effects are to be produced, being about sixty grains. For other purposes from five to ten grains usually suffice. Although not manifesting any toxic activity when administered in the doses mentioned, it is quite inconceivable that an agent containing so much carbolic acid, liberated in the intestine, should not have the powers of a poison if given in sufficient amount. We repeat the caution already given, and advise our readers to avoid any excess in prescribing it for the purposes to which it seems to be so well adapted.

Therapy

If the intestinal reaction asserted by Sahli really occurs, a rational explanation is thus afforded of the curative action of salol in catarrhal states of the intestinal mucous membrane. In duodenal catarrh, catarrh of the bile-ducts and gall-bladder, in inspis-sation of the bile, and in jaundice, it must prove one of our best remedies, if the observations thus far made are confirmed by future experience. It is said to liquefy the bile; hence its remarkable utility in that state of the bile known as inspissation, in which deposits form in the ducts, thus causing at last occlusion; but, unlike calculi in this respect, the masses of inspissated bile occlude slowly, while the calculi block the canal suddenly. By rendering the bile more fluid, salol contributes to the solution of inspissated bile and of calculi, provided there be in the calculus a break in the continuity of its smooth surface (Levachoff).

Salol has also the antipyretic property of its congeners, probably in a higher degree than any member of the group. It is the more valuable as a remedy for fever, because it has no taste, and does not disturb the stomach. It has another important advantage: the rise of temperature which comes on after the conclusion of the antipyretic action is not accompanied by the chilliness, the rigor, and that profound depression of the vital powers approaching collapse, which seem to be necessary to the action of some—of nearly all, in a greater or less degree—of the newer antipyretics.

The first triumphs of salol were won in the treatment of acute rheumatism, excelling, as it apparently does, all other remedies in its power to abate pain and lessen fever. If all the conditions be propitious, by the end of the second or third day fever and joint-pain and swelling will have disappeared; but the rule of practice applicable to all other remedies is equally applicable to salol—that it is necessary to keep up the remedy after the active symptoms have ceased, because of the danger of relapses. The duration of the salol treatment is determined by the success in avoiding relapses for the most part. It does not prevent cardiac complications, any more than do other remedies. The author has reason to believe, indeed, that a larger percentage of the cases now present the evidences of heart mischief since the use of remedies which so much try the heart by their action on the vascular tension.

It is now quite certain that salol and other remedies of the same class have the power to relieve the pains of locomotor ataxia in a remarkable degree. This fact is the more interesting because heretofore only the ordinary anodynes were available for this purpose. Recent experiences have brought to light, also, that the antiseptics—chinoline derivatives—have analgesic power of a peculiar kind, in that they afford remarkable relief in painful affections due to a pathological condition of the peripheral nerves, such as that present in locomotor ataxia, neuritis, etc. In this group we may include the cases of genuine migraine, and that large and indeterminate class, called rheumatic, of which lumbago, sciatica, and myalgia are representatives. The dose of salol for these purposes will be from three to ten grains, three or four times a day.

The topical applications of salol are deduced from its physiological actions. It is applied in the form of powder, dusted on the surface or blown on by an insufflator; in solution dissolved in alcohol, turpentine, or cotton-seed oil, and mixed with vaseline or other fats. As it has no odor, and is more effective than iodoform, its utility is evident. It can be mixed with iodoform or iodol, and thus the actions of both may be carried on simultaneously.

Admirable results have been obtained from it in ozoena, otorrhoea, gonorrhoea, in chancre, and chancroid ulcers, specific and common.

If the experiences of the future justify the statements of the promoters of salol, it will prove a valuable addition to the resources of therapeutics, especially in the numerous morbid states where a germicide only can remove the source and cause of all the mischief.