Before Sertürner had definitely established the nature of alkaloids, Vauquelin had separated from tobacco a substance which he regarded as its active principle, and which was undoubtedly an impure nicotine. This was in 1809. The alkaloidal character of this extract was not, however, recognised until 1828, when Posselt and Reimann produced it in a pure form.
Vauquelin had in 1812 extracted daphnine from mezereon root, and in describing his experiments had alluded to its alkaline character. For this reason the credit of having been the first to have discovered an organic alkali has been attributed to him; and when in 1818 Pelletier and Caventou discovered an alkaloid in St. Ignatius’s beans, to which they gave the name of strychnine, they stated that it had been their original intention to designate the substance Vauqueline in honour of the celebrated chemist who had first established the existence of an organic alkali. It had, however, been pointed out to them by distinguished members of the Academy that it would have been a doubtful compliment to associate such an honoured name as that of Vauquelin with such an evil (malfaisant) substance as this new product.
A number of chemists narrowly missed the discovery of quinine. As early as 1746 Count Claude de la Garaye obtained from cinchona bark a crystalline salt which he termed sel essentiel de quinquina. Two other French chemists, Buquet and Cornette, subsequently introduced another sel essentiel de quinquina. Both these products were simply kinate of lime. A Swedish physician named Westerling announced in 1782 that he had discovered the active principle of cinchona, and he gave it the designation of vis coriaria. His product was in fact cinchotannic acid. Seguin perhaps made the worst mistake of all the investigators in coming to the conclusion that what was precipitated by tannin was the essence of cinchona from a medicinal point of view, and he actually recommended that gelatin should be substituted for cinchona in cases when price was an object. Fourcroy made several attempts to ascertain the true chemical constitution of the bark. In 1790 he separated a resinous principle, mixed with some colouring matter, since called cinchonic red. This he at first supposed was the essential medical constituent of the bark. Vauquelin later adopted this erroneous theory, and so missed his way. In 1792 Fourcroy got nearer to the truth when he observed incidentally that the water in which the bark had been macerated turned litmus paper green; and he also remarked that lime water caused a greenish precipitate in the infusion. He did not pursue the investigation, but his comment on what he had stated is noteworthy. “These researches,” he said, “will no doubt lead to the discovery one day of an anti-periodic febrifuge, which once known may be extracted from various vegetables.” Berthollet followed on Fourcroy’s lines, but came to the conclusion that the precipitate which lime water gave with decoctions of cinchona was magnesia, which he believed was a constituent of the bark in combination with hydrochloric acid.
In 1811 Gomez, of Lisbon, described a crystalline substance which Dr. Duncan, of Edinburgh, had obtained from certain species of cinchona, and gave to this product the name of cinchonine. Lambert later prepared it in a state of considerable purity. But neither of these chemists suspected its alkaline nature. In 1820 Pelletier and Caventou studied the whole chemistry of cinchona and succeeded in showing that the cinchonine of Gomez was a mixture of two alkaloids, to the second of which they gave the name of quinine. Quinidine was isolated by Henry and Delondre in 1833, and cinchonidine by Winckler in 1844, but the name of the latter was given by Pasteur in 1853. Pasteur also produced the alkaloidal derivatives cinchonicine and quinicine.
Robiquet had the idea that as the coffee plant belongs to the same family of plants as the cinchonas it might be possible to find quinine in coffee. In searching for it he isolated caffeine. This was in 1821. In 1827 Oudry found an alkaloid in tea and called it theine. Jobst and Mulder in 1838 proved that these alkaloids are identical. It is now recognised that the alkaloids of cocoa, of guarana, and of Paraguay tea are all the same substance, or closely related.
Pelletier and Caventou isolated strychnine from the St. Ignatius beans in 1818, and brucine from false angostura bark (Brucæa anti-dysenterica) in 1819; in the same years they obtained veratrine from cevadilla seeds and white hellebore root; but it would appear that in their investigation of cevadilla seeds, which was the first to yield the alkaloid, they were preceded by a very short time by Meissner. Pelletier and Magendie produced emetine from ipecacuanha in 1817, and Pelletier alone is credited with narceine in 1832. Codeine was discovered by Robiquet in 1821 when he was examining a new process for obtaining morphine which had been suggested by Dr. William Gregory, of Edinburgh. Belladonna had been studied by Vauquelin and many chemists after him, but it was not until 1833 that atropine in a state of purity was isolated from it. This was accomplished simultaneously by Geiger and Hess, two German chemists, and by Mein, a German pharmacist.
ANÆSTHETICS.
The greatest triumph achieved in any department of medicine, and worthy, perhaps, to be described as almost, if not quite, the most beneficent discovery in the world’s history, is that of the successful employment of anæsthetics. This great glory belongs to the nineteenth century. Indian hemp had been employed for centuries in the East, mandragora had a classical reputation, and from time to time the possibilities of hypnotism had been expounded by one or another of its professors. But it is only within the past sixty years that the terrible anxiety and suffering associated with surgical operations have been so far mitigated as largely to increase the prospects of success, and to annihilate the pain. To Sir Humphry Davy is due the credit of first suggesting the line of advance towards this precious goal by describing his experiences of the inhalation of nitrous oxide gas which he found had the effect of relieving toothache and other pains; “uneasiness swallowed up for a few minutes by pleasure,” were his own words; and he foresaw the possibility of this agent being employed as an inhalation “in such surgical operations as involved no great effusion of blood.” That was in the year 1800. About 1830 Faraday observed and noted the effect of ether on the nervous system, which he stated was similar to that of nitrous oxide gas.
Horace Wells.