The celebrated fever powder of Dr. James was evidently not his original composition, but an Italian nostrum invented by a person of the name of Lisle, a receipt for the preparation of which is to be found at length in _Colborne’s Complete English Dispensatory for the year 1756_. The various secret preparations of Opium, which have been extolled as the invention of modern times, may be recognized in the works of ancient authors; for instance, Wedelius in his _Opiologia_ describes an acetic solution; and the _Magisterium_ of Ludovicus, as noticed by Etmuller, was a preparation made by dissolving Opium in vinegar, and precipitating with Salt of Tartar;[70] Van Helmont recommends a preparation, similar to the black drop, under the title of _Laudanum Cydoniatum:_ then again we have Langelott’s Laudanum, and Le Mort’s “_Extract out of Rain water_,” preparations which owe their mildness to the abstraction of the resinous element of opium. The works of Glauber contain accounts of many discoveries that have been claimed by the chemists of our own day; he recommends the use of muriatic acid in sea scurvy, and describes an apparatus for its preparation exactly similar to that which has been extolled as the invention of Wolff; he also notices the production of _Pyro-acetic Acid_, under the title of “_Vinegar of Wood_,” so that the fact of the identity of this acid and Vinegar, so lately announced by Vauquelin as a _New Discovery_, was evidently known to Glauber nearly two centuries ago. We have within the last few years heard much of the efficacy of Henbane fumigations in the tooth-ache, an application which may be easily shewn to be the revival only of a very ancient practice.[71] But while we might thus proceed to annul many other claims for originality, we ought not to close our eyes to the fallacies to which such investigations are peculiarly exposed. Nothing is more easy than to invest the doubtful sentence of an obscure author with an interpretation best adapted for the support of a favourite theory, and instances might be adduced where the medical antiquarian[72] has by violence and distortion forced the most contradictory passages into his service; treating, in short, the oracles of Physic just as Lord Peter treated his father’s will in the _Tale of a Tub_,—determined to discover the word “_Shoulder Knots_,” he picks it out, letter by letter, and is even at last obliged to substitute C for K in the orthography.