The applications of salicylic acid in the treatment of disease are based on the results of the physiological examination. In the diseases of the stomach characterized by fermentative changes in the food, as in catarrh, dilatation of the organ, etc., salicylic acid is an effective remedy. The author has seen admirable results from its use in gastralgia, even when distinctly periodical. In the vomiting of a pasty, fermenting mass of ingesta, whether or not accompanied by the organism, sarcina, or other germs of fermentation, good results are derived from this remedy. In these stomachal disorders, the best effects are had from ordinary doses (five to ten grains), given in a wafer, either in anticipation of the attack—as of gastralgia appearing at a fixed hour—or during the process of fermentation in the stomach contents. As a portion of the remedy taken passes into the faeces, it is probable that salicylic acid is just as effective in the corresponding troubles in the intestines. Ilgin reports the removal of taenia solium in six cases by the administration of salicylic acid, in eight-grain doses every hour until five doses were taken—preceding and following the acid with a dose of castor-oil. It has been employed successfully in the removal of ascarides, by local application and by internal administration. An enema of water should precede the salicylic-acid solution, which may be composed of borax and salicylic acid with some glycerin. Rx Acid, salicylic, 3 ss; sodii biborat., 3 ss; aquae, Oj. M. Sig.: Warm, and administer the whole amount at one time. For a young child, this quantity should be reduced one half, or more.

When the heart is weakened from any cause, salicylic acid and salicylate of soda must be exhibited with caution. The experience thus far accumulated warrants the assertion that the dose of fifteen grains of the former and twenty of the latter should rarely be exceeded, if frequent repetition of the dose is practiced. From Riess, who regards salicylate of soda as a specific in typhoid fever, to Filatow, who holds that it is worse than useless, there are various shades of opinion, with the weight of authority decidedly in favor of the view that it is a remedy of real value. Since Riess, no one has claimed in this remedy a specific for typhoid, but it is generally admitted that it renders the course of the disease milder by keeping the temperature within safe limits (Tomkins, Hallopeau, Butt, Immermann, Senator, etc.). Weiss concludes, after an experience of ninety-six cases of typhoid in children, treated with salicylate of soda, that it is a powerful antipyretic in the typhoid of children, and that, while it does not shorten the course of the disease, it renders it much milder. He finds that the results are better, when the typhoid of children is treated by salicylate of soda, than have hitherto been obtained from quinine and cold baths. A still more recent English experience is to the same purport as the German. Dr. Tomkins finds that in the salicylates we have the means of reducing fever-heat, more certain and more agreeable than by the cold bath. In the eruptive fevers, the same principles obtain as in typhoid. Salicylate of soda is preferable to salicylic acid, because it is less irritating, safer, and equally effective as an antipyretic. The object of its administration is to reduce the heat, which is the most important source of danger. The amount required to accomplish this object is now definitely known. Twenty grains of the soda salt may be given every two hours, until the temperature is reduced to the proper point, at which it may be held by ten-grain doses at the same interval, unless the occurrence of an exacerbation requires the exhibition of a larger quantity. In the case of children, the daily quantity ranges from half a drachm to a drachm. Probably the best mode of administering the salt is in the form of wafer, but when these can not be obtained, a solution may be readily prepared, or the salt may be constructed extemporaneously by adding the acid to a solution of sodic carbonate as follows: Rx Acid, salicylic, Э iv ; sodii bicarbonat., 3 j; aquae, oz jss; syrup, simpl., oz ss. M. A table-spoonful contains about twenty grains salicylate of soda. It should be borne in mind that this remedy is not safe if the heart is very weak, or if albuminuria is present.

In relapsing fever, according to Riess, salicylic acid accomplishes something more than the mere reduction of temperature. Although it does not prevent the usual relapse, even when administered in large doses during the interval, it lessens the severity and duration of the relapse. It does not destroy the spirilla in the blood, nor indeed lessen their activity (Riess), and hence can not be a curative agent in this disease. In pyaemia, septicaemia, puerperal fever, diphtheria, etc., salicylate of sodium is used under the same rules as in typhoid. The indication for its use is high fever, and the good accomplished by it is determined by the degree in which the temperature is reduced. The antiseptic action is quite secondary to the antipyretic. In malarial fevers it was supposed by Senator and others, in the enthusiasm attending the introduction of the remedy, that salicylic acid would prove equal to quinine. If administered in a full dose just before the advent of a paroxysm, it will prevent it, but it does not possess the curative powers of quinine over the effects of the malarial poison, and hence will not prevent relapses. By using salicylate of sodium to abort an impending paroxysm, and quinine to prevent relapses, the curative result will be attained with the least pecuniary expenditure. In the mildest cases of intermittents, salicylate of sodium may be depended on alone, but, to succeed, it must be administered before the expected paroxysm.

Out of the enormous mass of published experience in regard to the value of salicylic acid in acute rheumatism, it is difficult to select. From the first trials of Buss, followed by Stricker and Traube, there has been an almost unanimous expression of opinion by the German physicians in regard to the value of this agent in rheumatism. At first it was supposed that the disease could be invariably cut short in forty-eight hours to three days, but larger observation has qualified these opinions. By way of illustration of the measure of success now attained in Germany with salicylic acid in rheumatism, we may take the recently published statistics of Diesterweg. Of one hundred cases treated with this remedy, the disease was cut short in thirty-six or twenty-four hours; in eighty-five, within the period of forty-eight hours; in ninety-eight, within seventy-two hours; in one the disease was prolonged to eighty-four hours; and in one the remedy had no effect on the disease. It is not intended to convey the impression that the cases got well in so short a time, only that the fever and joint-swelling and pain subsided, and convalescence was established. Relapses occurred in eleven cases, and cardiac complications in five.

In France the treatment of acute rheumatism by salicylic acid was taken up by Jaccoud, Lepine, Gueneau de Mussy, and others, but especially by Prof. See, who has devoted to it several important lectures. As a result of See's observation, he concludes that salicylic acid has a marked and peculiar benefit in acute rheumatism; that the pains invariably cease in from twelve to eighteen hours; that the articular swelling disappears at the end of three days, and that the fever subsides with the pains. If the fever persists, other joints will become affected. Out of fifty-two cases treated by Prof. See, fifty-one recovered in from two to three days. These results are quite equal to the German. See makes an important observation in regard to the rapidity with which salicylic acid and salicylate of sodium are eliminated, and the necessity, therefore, of continuing the remedy for some time after all the joint-troubles have ceased, to prevent relapses. Prof. Gubler does not share the general enthusiasm as to the value of this agent in rheumatism. He emphasizes the uncertainty and the dangers attending its use, and maintains that it has no antipyretic effects.

In England salicylic acid and salicylate of sodium have been used with a large measure of success, but the rheumatism of England, as of this country, does not yield with the promptness characteristic of the Continental disease. The general results of the treatment, as conducted in England by Broadbent, Carafy, Spencer, Boggs, Greenhow, and many others, is very much as expressed by the last-named in his important communication to the Clinical Society. The temperature speedily falls, sometimes within a few hours and almost always in two or three days, the pulse declines at the same time, the pains subside correspondingly, and the joint-swelling diminishes and disappears within three or four days. Greenhow points out that such a result is not a cure even in the most favorable cases; that the remedy acts very injuriously on the heart and causes a deep anaemia, and that, therefore, the duration of the disease, from beginning to the termination, is not actually shortened. Dr. Maclagan (also Charteris) strongly urges the substitution of salicin, on the ground that it is equally effective with salicylic acid and much less dangerous; but it is difficult to appreciate this argument, since salicin is converted into salicylic acid in its passage through the system.

In this country, the experience of the Maine physicians, and of the medical staff of the Massachusetts General Hospital, has been published, and all concede that it has good effects. As regards the experience at the Massachusetts General Hospital, the facts are as follows: In eight cases out of seventeen treated with salicylic acid, the duration. of the longest case was twenty-six days, and the shortest five days, the improvement being very marked from the beginning of treatment. Of three patients who took salicylate of soda only, the duration of the disease was less than twelve days in each case, the shortest being two days. In the remaining nine cases the duration was six weeks or more.

In summing up the testimony, it is clear that salicylate of soda is a most valuable remedy in acute rheumatism, but various unpleasant, even dangerous symptoms arise in some cases. Violent headache, vertigo, and tinnitus aurium, are common; wild delirium is an occasional symptom; weakness of the heart, obscuration of the first sound, and profound anaemia, are especially noted by Greenhow; very great gastro-intestinal disturbance is now and then produced. Empis narrates a fatal case of acute rheumatism which was treated by salicylic acid. Great depression of the powers of life, in rare instances approaching collapse, has been observed. Sufficient is now known of the danger attending the salicylic medication of acute rheumatism, to justify the author in urging circumspection on the attention of his readers. The robust and vigorous rheumatics are proper subjects for this treatment, whereas, in the pale, feeble, and cachectic, especially those with weak hearts, this treatment must be pursued cautiously, or not undertaken at all. Relapses are frequent, probably because of the very rapid elimination of the remedy, as suggested by Prof. See, and hence its administration must be continued for some time after all of the local and systemic symptoms have subsided.

In gout, chronic rheumatism, myalgia, and lumbago, salicylate of sodium often acts most serviceably. It is more effective the more acute the malady, as a rule, but it sometimes does great good in the most chronic cases. Abbott reports the cure of sciatica, and Brun of rheumatismal irido-choroiditis, by its use. The author has succeeded in some instances very promptly in the cure of sciatica by the salicylate of soda—the formula used being that for the extemporaneous solution. The cases in which this remedy has proved most efficacious, were those of functional disturbance in the nerve, the muscles being in their normal condition, and the pain having nocturnal exacerbations.

It is a very interesting fact, first distinctly stated by Dr. Pye Smith, of Guy's Hospital, London, that, during the administration of salicylic acid and the salicylates, the urine exhibits the reaction for sugar on the application of Trommer's test. This has been observed in rheumatism and in other diseases treated with this agent. The urine is a little increased in amount, but its specific gravity is not changed. The reduction of the copper is effected by the acid or by the glycogen, which is one of the products of the decomposition of salicylic acid. Müller, the assistant of Eckstein in the clinic at Kiel, has published some important observations on the use of salicylate of soda in the treatment of diabetes. It appears that full doses of the salt cause the sugar to disappear entirely, but this is not a permanent result, for, after a time, the sugar returns. A very great tolerance to the remedy exists in this disease, and large doses may be taken with impunity. Bouchardat, in commenting on these observations, states that he has not had good results from this treatment. Since, however, the remedy is well tolerated, and during its exhibition in considerable doses the sugar disappears, it may be used with advantage at critical times to stop the waste.

Salicylate of sodium has feeble antiseptic properties, and hence salicylic acid, which is even superior to carbolic acid in its power to destroy minute organisms and to prevent change in putrescible materials, should be preferred for all topical applications. Being free from odor, and more active than carbolic acid, it should be used instead of carbolic acid for most purposes. For all toilet purposes, it is decidedly preferable. It is an excellent addition to the ordinary powder dentifrices, and its solution with borax is an efficient deodorant in fetid perspiration. This disagreeable affection, as it attacks the feet, may be relieved by dusting the feet thoroughly with powdered salicylic acid before putting on the stockings. It is useful, also, to fill the interstices of the stockings with the powder. Extraordinary success has been achieved by the local application of this remedy in eczema of the head and face. Those cases characterized by much weeping seem to be best adapted to the cure by salicylic acid, but eczema rubrum and eczema impetiginodes, that resisted other approved means, have yielded to the application of this agent (Wagner, Will). It is generally conceded that, as a local application to syphilitic ulcers, salicylic acid is inferior to carbolic acid.

The most important of the topical uses of salicylic acid are in the antiseptic treatment of wounds and injuries. When it was shown that this agent had a power to destroy the activity of ferment and disease-germs equal to that of carbolic acid, while it is free from the irritating quality and disagreeable odor of the latter, Thiersch, who is a strong advocate for Lister's antiseptic method, resorted to the use of salicylic-acid solutions. Further experience has, however, rather proved the superiority of carbolic acid in respect to the germicide and antiseptic properties for which these remedies are now so largely employed.

To cancer, gangrenous and sloughing wounds, pure salicylic acid may be applied in powder. To prevent the contact and multiplication of atmospheric germs, operative procedures may be conducted in salicylic spray, the sponges and dressings may be saturated with salicylic solutions, and the wound irrigated by the same. In order to carry out all the details of the antiseptic method, salicylic acid is substituted for carbolic in the forms and combinations of dressings employed by Lister. Wounds are covered with cotton-wool, impregnated with an alcoholic solution of the acid in the proportion of 3 and 10 per cent. As cold water takes up only 1 part to 300, which, however, is strong enough to destroy bacteria, etc., the addition of borax is generally necessary to obtain a solution of sufficient strength for the antiseptic applications. A salicylic-acid plaster may be prepared as follows: Salicylic acid, 3 ss—3j; white wax, 3j; paraffin, 3 i j; almond-oil, 3 ij. The ingredients are melted, and rubbed up together in a heated mortar (Will), and spread on muslin. An ointment more readily melted by the heat of the body is the following: sperm-oil, 3 jss; cacao-butter, 3 vss; salicylic acid, 3 ss— 3 j. This should be melted together, thoroughly incorporated, and spread on lint (Will). An ointment for the same purposes may be prepared in a simpler way by the addition of salicylic acid to simple cerate. A solution of salicylic acid in olive-oil, in the proportion of one drachm to eight ounces, is an efficient local application for burns.

Authorities referred to:

Bose, Dr. H. Berliner klinische Wochemchrift, 1875, No. 28.

Buss, Dr. E. Die antipyretische Wirkung der Salicylsäure. Cent. f. d. med. Wissen-scha/ten, 1875, No. 18.

Furbringer, Dr. Zur Wirkung der Salicylsäure, pamphlet, Jena, 1875.

Immermann, Prof. Quoted in Liebermeister's Handbuch der Pathologie und Therapie des Fiebers, Leipzig, 1875, p. 644.

Kolbe, Prof. Ueber die antiseptischen Eigenschafter der Salicylsäure. Schmidt's Jahr-bücher, vol. clxiii, p. 229.

Letzerich, Dr. Ludwig. Experimentllen Uhtersuchungen und Beobachtungen über die Wirkung der Salicylsäure bei der Diphtherie. Virchow's Archiv, Band lxiv, p. 102.

Moeli, Dr. Berliner klinische Wochenschrift, 1875, No. 30.

Senator, Prof. Dr. Berliner klinische Wochenschrift, No. 32.

Squibb, Dr. E. Note on Salicylic Acid, Brooklyn, 1875.

Thiersch, Prof. Dr. Klinische Ergebnisse der Lister'schen Wundbehandlung, etc. Volkmann's klinische Vorträge, Nos. 84 and 85.

Traube, Dr. L. Berliner klinische Wochenschrift, No. 1, 1876.

Will, Dr. J. C. Ogilvie. On Salicylic Acid. The Lancet, vol. ii, 1875, p. 870, et seq.