Peruvian Or Jesuits Bark Cinchona, named in honor of the countess of Chinchon, the wife of the viceroy of Peru, who, having been herself cured thereby, is said to have first carried the bark to Europe, where she used it successfully in the cure of intermittent fever about 1640. Soon after its introduction into Spain, the Jesuits began to receive it from their brethren in Peru, and through them it was spread over Europe, in consequence of which it was called Jesuits' bark. It is the dried bark of many species of the genus cinchona, a tree belonging to the order rubiacem and suborder cincJionaccce. Until very recently it has been impossible to determine with accuracy from which species of cinchona the different varieties of bark were obtained, but late investigations with the aid of chemistry have thrown much light upon this subject, though something yet remains to be learned. Although each species or even variety of cinchona may be supposed to produce a separate kind of bark, and although these varieties run into each other in such a way that hardly any two botanists agree as to the proper lines of separation, yet the commercial products may be divided into three classes, yellow, red, and gray barks.
To these may be added the non-officinal or Carthagena barks, brought from the northern Atlantic ports of South America. The three varieties first mentioned are obtained from Pacific and South Atlantic ports. The source of the yellow bark is said by the " United States Dispensatory" to be G. calisaya, one of the largest and finest species, growing in Peru and Bolivia. A va-riety of this species, G. Joscphiana, is but little more than a shrub. The bark of G. Boliviano,, and the better pieces of C. oxata, C. scrobicu-lata, and C. micrantlia, are probably often mixed with the parcels of calisaya bark. The first mentioned species is by some botanists regarded as a variety of G. calisaya. The red bark is derived from C. succirubra, a largo tree, growing upon the western slopes of Chimborazo and the neighborhood. C. nitida is also indicated by Weddell as a source of this variety. The pale or gray barks are referred to C. Condaminea and G. micrantha by the " United States Dispensatory," but other species (G. ovata, scrobiculata, macrocalyx, and uritu-singa) probably contribute to the supply.
The Carthagena barks are probably derived partly from some of the same species with the kinds just mentioned, and partly from G. cordifolia, G. lancifolia, and G. Pitayensis. Some of them are of very good quality, and are extensively used for the extraction of the alkaloids. The "false" barks are derived from inferior species of cinchona and allied genera. - The cinchonas appear to thrive best in regions subject neither to extreme heat nor extreme cold, where a somewhat even temperature prevails throughout the year, and where they are partially protected by their neighbors from the direct rays of the sun. These conditions are fulfilled upon the slopes of the Andes between lat. 10° S. and 10° N. For more than a ccn-turv after Peruvian bark came into use, it was supposed to exist only in Loxa in the ancient kingdom of Quito, and in a few neighboring localities; but in the year 1753 it was discovered may arious other places of a corresponding elevation with Loxa above the sea. Little advantage, however, resulted from this; but some 20 years Inter, under the patronage of the Spanish government, researches were made in New Granada, which resulted in the discovery of several species of cinchona.
At a subsequent period supplies of the bark were obtained from other sources, which arc now shipped from many of the South American ports, including some ports in the Carihbean sea. Considerable care and experience are necessary in collecting the barks, to select those most valuable, and to know the proper age at which a branch should be decorticated. The bark is collected between May and November. The tree is usually cut down and then stripped, which is the most economical plan, as fresh shoots spring up from the old roots. But the Indians, to save themselves the trouble, often strip the bark entirely from the tree while it is standing, thus destroying it altogether. Owing to the reckless manner in which the bark has been collected, and the entire absence of any efficient protection to the forests on the part of the government or provision for the cultivation of the trees in plantations, the danger of a serious diminution in the supply of this valuable drug is by no means a remote one. For many years all the large trees of valuable species have disappeared from easily accessible regions.
Dr. Weddell in 1847, in order to see the G. calisaya in its full vigor, was obliged to make long journeys on foot through the forests, and endure the hardships and privations of the poor cascarilleros or bark collectors. The Dutch and British governments have made successful attempts to introduce the cinchona into their East India possessions, in Java, and various parts of Hindostan, where the mountainous regions furnish the necessary temperature and moisture for their growth. It has been found that the yield of some species of cinchona in alkaloids may be much increased by covering the bark with moss, and also that a longitudinal strip of bark may each year be taken from a tree without destroying it; the decorticated portion renewing, if "mossed," its former covering, at least as rich in alkaloids as before. Bark from the English plantations has already been introduced into commerce. More or less successful attempts at cinchona culture have been made in Jamaica, the isle of Reunion, Guadeloupe, Brazil, the Azores, and Algeria. It is possible that situations may be found within the limits of the United States suitable for the culture of the cinchonas.
The division of the bark into flat and quilled is determined simply by the part of the tree from which it is taken, whether trunk or branches, and the method of drying it, whether under pressure or allowed to roll up. - The medicinal value of Peruvian bark depends upon the alkaloids which it contains. These are quinia, cinchonia, quinidia, cincho-nidia, quinicia, and cinchonicia. Another alkaloid called cincine is found in small quantity in some of the inferior varieties. It is probable that the three latter alkaloids are artificial derivatives from the former. In addition to these, the bark contains in varying proportions gum, starch, ligninc oil, yellow coloring matter, insoluble red coloring matter, soluble red coloring matter or cincho tannic acid, kinic and kinovic acids. The various alkaloids are produced in the bark itself, and that probably by a reaction between the ammonia, which (according to De Vry) is everywhere contained in the plant, and the cincho-tannic acid. The general condition of the alkaloids is that of being more pure and easily separated from adventitious substances in the bark of the branches, somewhat less so in that of the trunk, and of all most impure in that of the roots.
Quinia, the most important of the alkaloids, has the formula C40H24N2H4, is crystal-lizahle, slightly soluble in hot and cold water, and very soluble in alcohol, ether, and chloroform. It forms crystallizable salts with several acids. It may he precipitated as a hydrate from a solution of a salt by an alkali or alkaline earth. Ammonia in excess redissolves the precipitate. Sulphate of quinia, or more properly the disulphate, is the medicine commonly known as quinine. It consists of one equivalent of sulphuric acid, 40, two of quinine, 324, and 8 of water, 72=436. It is in fine, white, silky crystals, which on exposure to the air effloresce and lose their form together with their water of crystallization. It dissolves in 30 parts of boiling water, but separates on cooling. In ether it is slightly soluble. Alcohol when cold takes up one part in 60, and the diluted acids, tartaric and oxalic, dissolve it freely. In water acidulated with sulphuric or other acid it readily dissolves, and this property is taken advantage of in administering the medicine in a liquid form. The manufacture of quinine is extensively carried on in Paris, in Stratford, England, and in Frankfort, from which place Russia, Prussia, and Austria are chiefly supplied with this medicine.
In Philadelphia the business of extracting it from the bark is conduct-ed in chemical establishments also upon a very large scale. The quinine in the process of its extraction is commonly converted into the sulphate, which is the salt chiefly employed in medicine, and of which from 2.5 to 3 per cent, is usually obtained from the yellow hark. The processes employed vary somewhat in different countries. From a strong decoction of the bark in water, acidulated with hydrochloric acid and filtered, the quinine may be set free from its combination with kinic acid and precipitated by addition of lime water; some lime combined with coloring matter falls with it. The precipitates are well washed with water, and the residuum is pressed, dried, and pulverized. It is then repeatedly treated with alcohol, which dissolves the quinine and leaves most of the impurities. These being separated, the solution is concentrated by evaporation to a brown viscid mass, which is impure quinia; or the tincture in the distilling vessel may be neutralized with sulphuric acid, and the alcohol being then distilled off, an impure sulphate is obtained which crystallizes on cooling. This is expressed, and then dissolved in boiling water to which purified animal charcoal has been added.
It is filtered while hot, and then allowed to cool and crystallize. The purification is completed by again dissolving and crystallizing. Sulphate of cinchonia is commonly present, but being more soluble does not crystallize so readily as the sulphate of quinia, and remains in the mother liquor. This also contains what Liebig regards as an amorphous variety of quinine, which is analogous in its properties to uncrystallizable sugar; it is known as quinoidine, and possesses the same medical properties as the sulphate. It probably consists chiefly of quinicia and cinchonicia. The soluble salts of quinia form precipitates with tannic acid, with the soluble salts of lead and baryta, with a solution of iodine in iodide of potassium, and with the iodohydrargyrate of potassa. It is distinguished from the other alkaloids, with the exception of quinidia, by the production of an emerald green color when the solution is treated first with the solution of chlorine and then with ammonia, and which changes to a white or violet upon saturation with a dilute acid.
Some of the salts of quinia, especially the sulphate, possess the remarkable property, called fluorescence, of rendering visible as a pale blue the ultra-violet rays of the spectrum, and an exceedingly small quantity may be detected by examining even in ordinary light a long tube filled with its colorless solution. The test is much more delicate when the electric light is used. Hydrochloric acid or chloride of sodium renders the reaction much less distinct, or in ordinary light imperceptible. The sulphate of iodo-quinia, as well as the corresponding salts of the other alkaloids, possesses the property of polarizing light, in which it is equal if not superior to tourmaline. Quinidia is isomeric with quinia, and resembles it in many of its chemical reactions. It is distinguished from quinia by its greater facility of crystallization, its less solubility in ether, and its influence on polarized light. It forms a precipitate with iodide of potassium, a property possessed by no other cinchona alkaloid. Cinchonia has the formula C40H24N2O2, is crystallizable, only very slightly soluble in water, cold alcohol, and ether. It forms salts with acids. It is obtained chiefly from the pale barks.
Cinchonidia is isomeric with cinchonia, but differs from it in being more soluble in ether and also in its influence on polarized light. Commercial quinidia generally consists of quinidia proper with a much larger proportion of cinchonidia. Quinicia and cinchonicia are isomeric with quinia and cinchonia respectively, but are uncrystallizable. The different varieties of bark contain these alkaloids in varying proportions, the yellow yielding chiefly quinia, the pale a larger proportion of cinchonia with but little quinia, and the red a considerable proportion of each. According to the "United States Pharmacopoeia," cinchona bark should contain at least 2 per cent, of the proper cinchona alkaloids which yield crystallizable salts. - The cinchona alkaloids, and especially the sulphate or disulphate of quinia, are largely used in medicine. Their most striking and earliest discovered property is that of preventing an expected access of intermittent fever. For this purpose quinia should be administered in large doses. Two to 15 grains may be given at a time some hours before the expected chill, but not more than 30 or 40 grains should be given during the 12 hours preceding one. If administered subcutaneously, a smaller quantity will suffice.
It is also extensively used in other forms of malaria and diseases dependent thereon. For these uses, and also as a prophylactic (against malaria), quinia has been found almost as important to the traveller in malarial regions as a good supply of food. It has been said that the British rule in India is founded upon cinchona bark. A full dose of quinia reduces the pulse and the bodily temperature, and it has been applied in diseases not malarial, such as typhoid fever, erysipelas, pyemia, and rheumatism. It has until recently been difficult to explain the acknowledged therapeutic action of quinia by any well ascertained physiological action; but within a few years it has been discovered to possess certain properties which may serve as a clue to the method of its action in disease. It has been found that it is capable of arresting or delaying various kinds of fermentation, of killing the microscopic organisms accompanying putrefaction, of arresting the amoeboid movements of the white blood corpuscles, and of preventing the escape of these corpuscles from the mesenteric vessels of the frog, when prepared as in the well known experiment of Cohenheim. In animals poisoned by the injection of putrid fluids into the veins, it has been found that those to which quinia was administered lived longer than those without it.
The other alkaloids probably have the same power, but in a less degree. Cinchonia is about one half less powerful than quinia. The amorphous residue left after the crystallization of quinia may be used for the same purposes, but is inconvenient from the circumstance of there being no satisfactory test for its strength and purity. Quinia and the other alkaloids give rise to certain nervous symptoms, of which the most prominent are headache, a feeling of fulness and tightness in the head, buzzing in the ears, and temporary deafness. Permanent deafness is a rare accident. Quinia or the other alkaloids may be administered in the form of pills or in solution. In the latter form the intense bitterness is a serious objection to their use. This may be partially disguised by sirups, aromatics, extracts of licorice, dandelion, etc. Tannin renders quinia less bitter because less soluble. Various combinations of quinia with iron, strychnia, phosphorus, etc, are in use. When a simple tonic effect is de-sired, the preparations of the bark itself may be advantageously used.