So long ago as 1834 this substance was separated from coal-tar by Runge, and given the name Leukoline. Subsequently it was obtained by Gerhardt from the cinchona alkaloids, and by him the name chinoline or quinoline was assigned to it. Lately, chinolin has been produced synthetically by Skraup, by acting on aniline or nitro-benzol with glycerin in the presence of some dehydrating agent. Thus prepared, chinolin is an oily, highly refracting liquid and basic substance, which combines with acids to form salts. All of the salts, except the tartrate, are very deliquescent, crystallizing with difficulty, and soon losing their form; but the tartrate is in lustrous crystals, stable even in a damp atmosphere, and yet sufficiently soluble in water. According to Donath, chinolin is not more closely allied to quinine in physiological and therapeutical actions than it is chemically. Although these confident expectations, that in chinolin we have an adequate substitute for quinine, have not been realized, this remedy is still entitled to be regarded as a valuable antiseptic and antipyretic. Donath has shown that a two-per-cent solution will prevent the development of bacteria in decomposing solutions. Its power to reduce febrile heat is the same as that of the other agents of the group, except that it is greater. Indeed, chinolin is supposed to be nearly as active as quinine as an antipyretic. All of these phenol derivatives and congeners—resorcin, hydroquinon, pyrocatechin, chinolin, etc.—possess the power to reduce fever-heat, while they are powerless to affect the normal temperature. The fall of temperature is preceded by a short period of excitement—of increased rate of cardiac movement, warmth of the surface, flushing of the face, etc.; then perspiration begins, the temperature declines, the pulse slows and becomes weaker, and the respirations lessen in number. The degree of antipyretic effect, and its duration, vary with the different members of the group.