7o6 



THE TROPICAL AGRICULTURIST. 



[March i, 1883. 



and further that the proportion of alkaloid diminishes 

 as we go up the stem to the branches. 



Mr. David Howard has also shown that the nature 

 of the alkaloid varies according to the part of the 

 tree from which the bark has been taken. 



Cinchona Lancifolia, Soft Golomhian. — Of the barks 

 not used in pharmacy the most important are afforded 

 by C. Inncifolia and G. Pitayeiisis, natives of the Cordil- 

 leras of C'l'iumijia. These barks are largely imported and 

 used for miking quinine, the former under the name 

 of soft Colombian, Carthagena or Caqueta bark. The 

 bark of G. lancifolia varies much in appearance, but 

 is generally of an orange-brown ; the corky coat, which 

 scales oif easily, is shining and whitish. It also often 

 occurs in more or less curved or quilled pieces of 

 tolerable thickness, having externally the reaiains of 

 a whitish silverj' epidermis ; but their greatest dis- 

 tinguishing character is their very fibrous fracture. 

 Their anatomical structure, according to liinbury, 

 agrees, in all varieties, in the remarkable number of 

 thick-walled cells of the middle cortical layer and the 

 medullary rays. In percentage of alkaloids, Carthagena 

 barks are liable to great variation. 



The PiUiyo barks are restricted to the south-western 

 districts of Colombia, and are usually imported in short 

 flattish fragments or broken quills. The middle cortical 

 layer exhibits but few thick walled cells ; the liber 

 is traversed by very wide medullary rays, and is 

 provided with but a small number of widely scattered 

 liber fibres, which are rather thinner than in most 

 other cinchona barks. The Pitayo barks are usually 

 rich in alkaloids, quinine prevailing. C/vchona 

 Pitayciisis is one of the hardiest species of the valuable 

 cinchonas, and is, therefore, particularly suitable for 

 cultivation, which, however, has not been curried out 

 as largely as that of either C. officinalis or C. succiruby-a. 

 The hard Colombian bark of commerce, which occurs 

 usually in flat pieces and also in quills, is obtained 

 from C. cordifolia. The quills are usually large, heavy 

 and without periderm, with a fracture not so fibrous 

 as that of C, lancifolia (soft Colombian bark). The 

 flat pieces are thin, hard, somewhat curved, with the 

 remains of a white periderm. 



In reference to the fjrey barks of comnierce, C. micran- 

 tlia, C. nitidn and O. Peruviana; they abound in the 

 province of Huanuco, which is their principal source, 

 and are all imported under the name of Huanuco or 

 grey bark. The name of grey bark refers to the strik- 

 ing effect of ihe overspreading thallus of various lichens 

 belonging to the order Graphidac^ forming groups, and 

 indicating that the trees have grown in an open situation, 

 e.xposed to ram and sunshine. These b.-irks occur in 

 quills and flat pieces ; the former are eagerly sought 

 after by manufacturers on the continent, while the 

 flat pieces are just as readily sought for here, because 

 they very much resemble in appearance the flat calisaya, 

 for which at present they are very extensively sub- 

 stituted on account of tlie gi'eat scai'city of the latter. 

 They each yield from 2 to 3 per cent, of ciuohouine 

 and cinchonidine, with scarcely any quinine. 



Cinchona Calisaya, YcUow Bark (Cortex Cinchona: 

 Favaii:). — This valuable species was discovered by the 

 late Dr. Weddell in 1S47. It grows in the valley 

 forests on the borders of Bolivia and South Peru 

 (Carabaya). The bark was formerly imported in serons, 

 principally from Arica, the nearest port to the Bolivian 

 district of La Paz, where it was chiefly collected ; but 

 the supply of calisaya bark from its natural habitats is 

 at the present time very uncertain. The cultivatiou of 

 this bark in Inrlia has not been hitherto so successful as 

 that of C. succiriihra and C. officinalis, although recent 

 accounts have been more favourable. For its in- 

 troduction to India, as well as that of other species of 

 Cinchona, we are more particularly indebted to Mr. 

 Markham. Two varieties of this bark are distinguished 

 in commerce — flat aud quilled. 



Flat Calisaya. —The pieces of this bark are flat, or 

 nearly so," as their name implies. They are generally 

 uuooated, consisting almost entirely of liber, which is 

 sometimes J or nearly J an inch thick. Their texture 

 is compact and uniform; the transverse fracture is 

 finely fibrous, the filjres being short and readily detached, 

 so that when this bark is handled it causes much 

 irritation. Externally the colour is slightly brownish- 

 tawny yellow, frequently interspersed with darker 

 patches ; the surface is marked by shallow longitudinal 

 depressions, commonly termed digital furrows, whioh 

 are caused naturally on separating the periderm from the 

 liber, and not by the instrument used in detaching it as 

 formerly supposed. Internally the surface has a wavy 

 fibrous appearance ; the taste is very bitter — the bitter- 

 ness being gradually developed on chewing. The bark 

 of the root is readily known from that of the trunk 

 and branches, by occurring in short more or less curved 

 or twisted pieces. Calisaya bark is the best of ail the 

 cinchona barks; but little, however, is now obtained 

 from South America, our supplies being chiefly derived 

 froiTi plants under cultivation in India and .Tava. 

 One variety of Cinchona Calisaya, which has been 

 more especially cultivated in Java, aud known as 

 var. Ledyeriana, yields a bark of extraordinary rich- 

 ness in alkaloids. 



Calisaya bark is remarkable for the large amount 

 of quinine it contains, good qualities yielding at least 

 5 or 6 per cent of this alkaloid. 



Amongst other valuable barks which occur extens- 

 ively in the market must be mentioned cuprea bark 

 and the bark from C. indjcacens, a variety of C. rohiisld. 

 The cuprea barh, which of late has been imported 

 in enormous quantities, is furnished by two very dis- 

 tinct regions, viz., the base of the great eastern 

 branch of the Cordillera of the Andes, and the valleys 

 of the Rivers Meta and Guavire, aflJuents of the 

 Orinoco. The centre of exportation is Bacaramauga, 

 in the State of Santander. Cuprea bark is yielded 

 by trees belonging respectively to, at least, two dis- 

 tinct species which, though nearly allied, are yet 

 different from each other, and belong to the geuus 

 Remijia, which comes very near that of Cinchona aud 

 to the closely allied genus, Cascarilla. These species 

 are liemijia Purdicana and Remijia pcdunculata, Triaua. 

 The resemblance between the barks of the two species 

 is very great, and it wouM be ditficult to find char- 

 acters sufficiently marked to distinguish them. They 

 are both, in fact, hard, very compact, relatively heavy, 

 the inner surface smooth and of a wine-red colour ; 

 the epidermis is thin and striated longitudinally. The 

 cuprea bark which j'ields cinchonamine is, howeviir, 

 heavier and more compact and more filled with red 

 resinous colouriug matter, and its fracture generally 

 appears to be horny. The yield of quinine from cuprea 

 barks varies between 1 aud 2 per cent., according to the 

 conditions of vegetation of the trees, which have not 

 yet been sufficiently studied. From a chemical point; of 

 view, the characteristic and remarkable feature which 

 distinguishes the cuprea barks from the true cinchonas 

 is the absence of cinciionidine and the presence of a 

 peculiar alk.aloid called homoquiniue or ultraquinine, 

 the salts of which very closely resemble those of quinine. 

 Cinchona pubciccn" — This valuable bark is taken from 

 a hairy leaved tree, believed to be a hybrid between 

 C. Calisaya and Cinchona officinalis and on that account 

 was at one time called C. ujicinalis, var. jinbexccns. The 

 tree produces enormously thick bark and is one of very 

 rapicl growth. In a letter to Mr. Howard, Mr. Mclvor 

 writes, "If under all conditions this bark be found to 

 yield 12 per cent, of alkaloids consisting of 6 per cent, 

 quinine sulphate, it is ceriainly the best plunt we can 

 grow, being hardy aud of rapid growth, and perfectly 

 free from canker and other diseases to which the Calisaya 

 and 0///c-(«<(/i.s are liable." The appearance, therefore, 

 of these extraordinary plants, with their eooimous yield, 



