SALICYLIC ACID AND SALICYLATES. Salicylic, or ortho-oxybenzoic acid, occurs in a free state in the flowers of meadow-sweet (virea ni»utriu) and as a methylic ether in oil of wintergreen (gaultheria procumbens), from which it. may be obtained by distillation with potash. See GAULTIIERIA and WINTERGREEN, Oil of. The resulting salicylate of potassium is then decomposed by hydrochloric acid. It may also be obtained from salicine. indigo, and some other organic matters by adding to them hydrate of potassium healed to fusion. It is, however, more commonly prepared by heating carbolate of sodium in.a stream of carbonic acid gas. Carbolate of sodium in sclution is introduced into a retort and the carlionie acid passed through it ty means of a glass tube while heat is applied to the retort, gradually heating from 212' Fahr. to 428° Fmhr. and not higher than 464'. Carbonic acid enters into the molecule of carbolic acid (phenol), producing salicylate of sodium and carbonate of sodium, while one-half of the carbolic acid distils over. The following equation represents the reaction: 2 + = Na,C,II,O, C6140. The residue in the retort, is then dissolved in bpiling water, filtered, and decomposed by muriatic acid. On cooling, impure salicylic acid, having a reddidi-brown color, is precipitated in the form of a crystalline powder. In the last operation the reaction is as follows: 2lICI = 2 NaC1 C,I1606, which latter body is salicylic acid. Chloride of sodium (common salt) remains in solution. The impure acid is purilisd by dissolving it in boiling water or weak alcohol, treating the solution with animal charcoal, adding a little hydroshlorie acid, and crystallizing the filtrate. Squibb purifies by subliming with the aid of steam heat. By the above process the acid is obtained hi smell aelealar crystals; white, inodorous, and of an acrid, acid-sweetish taste. It may be obtained from the alcoholic; solution by spontaneous evaporation. in large, monoclinic p•ismi, and if the aq aeons boiling solution is slowly and carefully cooled it may be crystallized in long. slender needles of the shone crystal line formation. It requires about 1800 parts of cold water to dissolve it, and the aqnc 01153 solution imparts a deep, beautiful violet color to ferric salts. It melts a' to Fahr, and if carefully heated sublimes unaltered. By increasing the heat carbolic acid is given off. an 1 when still in we highly heated with powdered glass and quick lime it is decomposed into both' carbolic an 1 carbonic acids (CO, and 0). It deco:nooses carbon ites with effervescence, forming salicylates with the bases. Salley late of sodium is prepared in two ways: by neutralizing the acid with caustic soda or by neutralizing with carbonate an 1 bicarbonate of so la, evaporating to dryness in either ease. By the first method the composition of the salt is but by the second method. a mo1ecal3 of hydrogea replacing one of the sestinin molecules. Salicylate of ammonium is prep tied in :t similar manner by neu tralizing the acid with ammonia or carbonate of ammonia and evaporating, tlw acid salt crystallizing in needles. if the liquid is rendered alkaline by excess of ammo nia. the neutral salt will be formed. These salts are readily soluble in water. Salicylic acid and the salicylates, particularly the two just described, have been recently used to a considerable extent in medicine. Plants watered with salicylic acid die soon because the acid prevents tho3e organic changes necessary to assimilation. It will prevent the germination of seeds, acting in this respect like carbolic acid, be arresting the action of diastase oil the germ. This is the peculiar action of most organic antiseptic's. mid is the cause of its beneficial action as a medicine in eases Where it is applicable. Physiological action on animals: If a grain of salicylate of sodium is introduced under the skin of a frog the animal soon becomes languid and the heart paralyzed. When administered to
animals in sufficient doses it produces paralysis of the spinal nerves. Rochefontaine concluded that the acid, 1, impairs the general reflex sensibility by its action on 03 brain and spinal cord; 2. muscular contractility is suspended; 3, respiratory movements are suspendel: 4, the lic:irt's action is arrested More recent observers say that the primary action cf salicylate of sodium increases the cardiac force and that paralysis is a seconflary or reactionary effect The results of various experiments are conflicting. According to Furbringer the acid has no power in reducing the temperature in inflammatory fever, but has such power in septic fever. Zimmerman, however, found that septic fever resulting from injecting putrid fluids in the veins of rabbits was not controlled by the acid, a result which might have been es:pected. Such experiments have but little value to the medical pract itioner. As regards the effects of salicylic acid and salicylates upon the human organism. very large doses cause severe 119adaehe, muscular weakness and tremor, tingling in the extremities, and raising the pulse to 140 beats per minute. The urine gives a violet color on the addition of perehloride of iron soon after administra tion, showing a rapid passage through the system. It undergoes some change, however, in passing through the kidneys. because the urine does not have the power of checking fermentadon. The effects vary with circumstances and With different individuals. A patient 'having rheumatism took six drams of salicylate of sodium in the course of 22 hours, and suffered nu pain in the stomach, but the appetite was improved. In one case alarming symptoms, attended with delirium, followed the administration of one dram. Sometimes there is roaring iu the ears, disorders of vision. maniacal fury and loss of power in the limbs. Gastric disturbance sometimes takes place resembling that of corrosive poisoning. Children arc more apt to be affected in this way than adults. In one case of articular rheumatism a rapid cure was thought to be taking place, when buzzing in the ears, profuse sweats and extreme prostration came on, and the patient died suddenly.. Abelin states that acute nephritis (inflammation of the kidney) may occur during the use of the drug. A case of urticana is recorded as having taken place from its use. In acute inflammations there is much contradictory evidence in regard to the use of the medicine. One physician boasting of the antiphlogistic action of salicyline reported a mortality of 11 cases out of 35, an unfavorable result. In diphtheria some report favorable and others unfavorable, results. There is but little doubt. however, that when carefully administered in smaller doses than, unfortunately, are to- often employed in modern practice, it may prove beneficial in some cases of optic disease, and in hay fever. It has been reported to have cured cases of diabetes, but this may be doubted; it may have suspended the elimination of sugar by the kidneys, but sLch an action does not necessarily constitute a cure of this disease, which is one essentially of assimilation mid nutrition, depending usually or a profound affection of the nervous System, and not to begotten rid of in any summary manlier. As an external application it has been used with benefit in several skin diseases, but his probable that in all the cases in which it has been used internally and externally, an equal or better effect could have been accomplished by Minute doses and applications of carbolic acid. As to its administration, that is to be left entirely to the physician, whether given in the form of subdue (q.v.) salicylic acid or salicylates. It may be remarked here that when salicine is given it is converted in the organism into salicylic acid.