A manual of cinchona cultivation in India / by George King.

  • King, George, 1840-1909.
Date:
1876
Catalogue details

Licence: Public Domain Mark

Credit: A manual of cinchona cultivation in India / by George King. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

    12/94 (page 4)
    Chemical The most important and at the same time peculiar constituents of Cin- °fcimchona chona barks are the alkaloids enumerated in the following table 1:— Barks. ~ Alkaloid. Chemical composition. Cinchonine C20 H2t N2 O Cinehonidine (Quinidine of many writers) Quinine same formula. C20 Hct N* O2 Quinidine (Conquinine of Hesse) Quinamine same formula. C20 Hs6 N2 O2 There are other alkaloids, but they have no medicinal value so far as is yet known. These alkaloids exist in the bark in combination with certain organic acids called Kinic, Cincho-tannic and Quinovic. Of the alkaloids above mentioned the most valued is undoubtedly Quinine. Although Cinchona barks have been employed in Europe as febrifuges for the past two centuries, it was not until the year 1820 that any of the several active principles to which they owe their efficacy was obtained in a separate form. The first to he so separated were loidsirst' Quinine and Cinchonine.2 Quinidine3 4 was discovered in 1833 and Cinchoni- separated. dine * not until 1847- Quinamine was discovered so recently as 1872 by Hesse in bark of C. snccirnbra grown in Sikkim. Soon after the discovery of Quinine, the sulphate of that alkaloid began to be used by the faculty as a medicine in cases where some preparation of “ bark ” was required, and gradually the new salt drove out of fashion to a very large extent the powder, tinctures and decoctions of bark which formerly enjoyed such reputation in medical practice. Until the discovery of Quinidine and Cinehonidine, commercial Sulphate of Quinine consisted really of a mixture of the sulphates of all the Cinchona alkaloids, the outward appearance of these being alike. With the separation of the new alkaloids, chemical tests for their recognition began to be inserted in the various Pharmacopoeias and pure Quinine began to he insisted on in medical practice. The other alkaloids fell therefore into unmerited neglect, and they are still excluded from the British Pharmacopoeia. Their admission to the category of officinal remedies can, however, only he a matter of time, as their excellence as febrifuges, as will be subsequently related, has now been thoroughly established by the trials given to them by officers of the medical services of the three Indian Presi- dencies. Cinchona bark still continues to he rated by the European Quinine- makers in proportion to the percentage of Quinine it contains: the other alkaloids being counted for little or nothing as marketable products. These unsaleable alkaloids have accordingly been accumulating in the hands of makers in Europe, and are or were recently purchaseable at a comparatively low price.5 6 Regarding the proportion of these alkaloids in Cinchona hark, the learned authors of the Pharmacographia6 write as follows :— Proportion of “This is liable to very great variation. We know from the experiments of Hesse (1871) Cinchonam that the bark of C. pubescens Yahl., is sometimes devoid of alkaloid.7 Similar observations Bark. made near Bogota upon C. pitayensis Wedd., C. corymbosa Karst., and C. lancifolia Mutis, are due to Karsten. He ascertained8 that barks of one district were sometimes devoid of Quinine, while those of the same species from a neighbouring locality yielded 3^ to per cent, of sulphate of quinine. Another striking example is furnished by De Vry9 in his examination of quills of C. officinalis grown at Ootacamund, which he found to vary in percentage of alkaloids from 11’96 (of which 94 per cent, was Quinine) down to less than 1 per cent. Among the innumerable published analyses of Cinchona bark, there are a great number shewing but a very small percentage of the useful principles, of which Quinine, the most valuable of all, is not seldom altogether wanting. The highest yield, on the other hand, hitherto 1 .Pharmacographia, p. 320. 2 Discovered by Pelletier and Caventou. 3 Discovered by Henry and Delondre. 4 Discovered by Winckler, who named it Quinidine. 5 The following may be taken as approximates to the prices of the Cinchona alkaloids at the end of the year 1874:— s. d. ulph. Quinine per ounce ... ... ... ... ... 9 0 „ Cinehonidine „ ... ... ... ... ••• 2 6 „ Cinchonine „ ... ... ... ... ... 1 6 „ Quinidine „ ... ... ... ... ... 0 4 6 Pharmacographia, page 324. 7 Berichte der Deutsclien chem. Gesellsch., Berlin, 1871, p. 818. 8 Die med. Chinarinden Neu-Granada,’s, 17, 20, 39. 9 Pharm. Journ., September 6th, 1873, 181.