704 



THE TROPICAL AGRICULTURIST. 



[March r, 1883. 



A SUMMARY OF THE CINCHONA BARKS OF 

 COMMERCE. 



BY WILLIAM BLBORNE, 



Asiislant Curator of the Museum of the Pharmaceutical 



Society of Great Britain. 



ihe important genua Ciiiclioua gives its name to the 

 ordu- of wliich it is a member, namely, Cinchonacece. 

 B ■ auically the genus includes trees of various sizes, 

 s.ime reaching an altitude of 80 feet and upvvari's, 

 with evergreen leaves and deciduous stipules. The 

 flowers are of a white or pinkish colour, veryfragrunt 

 and airangeri iu panicles. The corolla i» salver shaped, 

 anvi nearly, if not quite, conceals the five stamens. 

 The ov.iry is crowned with a fleshy disc ; the style 

 simple ; the stigma two-cleft. The fi-uit is an ovate 

 capsule, grooved on both sides, crowned by the iimbof 

 tlie calyx, and dehiscing from below iipwards, in 

 order to allow of the escape of the numerous winged 

 seeds, whicli latter peculiarity is especially character- 

 istic of the order. According to the enumeration of 

 Bi ntham and Hooker, thirty-six species have been 

 diatiuguished ; but of these not more than about a 

 dozen have been economically utilized as furnishing 

 the eommercial cinchoua, or Peruvian bark. The plants 

 aie natives of the weoteru niuuutaiuous regions of 

 South Araeriaa, their geographical range extending 

 from 10° N. to 22' S. lat. and they fluui ish generally 

 at an elevation of from 5000 to SOOO feet above the level 

 of the eea, although some have been noted as growing 

 as high as 11,000 leet, and others have been found 

 down to 2600 feet. Of the commercial barks there are 

 several varieties they are as follows : — 



I. C. officinulia, var. a, Condayuhiea 1 yielding 



,, ,, h, Bonplandiana > crown 



,, ,, c, crispa ) bark. 



II. O. succirubra (Pavon) yielding red bark. 



Ill- lc:™"Sr yielding Colombian bark. 



IV. C. Pitayemif!, yielding Pitayo bark. 



( G. nilida ) 



V. < G. micrantha \ ,, grey bark. 

 ( C. Peruviana ) 



VI. C. Calisaya ,, yellow bark. 



,Trr ( Remijia Purdieana 1 • iv n i i 



The official barks of the British Pharmacopoeia nre 

 four in number ; — (1) The pale Loxa or crown bark 

 cortex, cinchona pallidic), yielded by Cinchona officinitlit ; 

 ((2) the yellow or Calisaya bark (cortix cincho/'Ce Jiai'ce), 

 the produce of C. Calimya ; (3) i lie r. d oark (cor<fx 

 cinchonce rubr<f), derived from C. succirubra ■ and (4j 

 Colombian bark, V. lancifolia, directed to be used as 

 a source of quinine. Ihese are the sources of the 

 tinctures, extracts and o'.h-r preparations, while, in 

 common with several othtrs, they also yield the 

 alkaloids which now ccnslitute tlie chief form in which 

 the active principles of ibe barks are administered in 

 medicine. Their great value depends upon tiie pre- 

 sence of these alkaloids, viz., quinine, qnin'dine, cin- 

 chonine and cinchouidine, which exist priucipa'ly in 

 the cellular tissue outside the liber, in coinbin ition 

 with kiuic and tannic acids. It is found that certain 

 barks contain more of one [iriuoiple than of another; 

 hence their greater or less comim rcial value, and the 

 skill and complex knowlicig.; lequ.red by the manu- 

 facturer to distinguish the different vaneties. The 

 G. Calisaya, C, officinalis and C. lancifolia from Col- 

 ombia are species rich in quiuine, which, in tlie form 

 of sulphate, is the alkaloid most extensively employed 

 in mediciae. Among the other barks used as .sources 

 of quinine, etc., the prmciples are :— Colombian bark, 



G. /awci/biia ; Pitayo bark, G. Pltayensis; grey or Lima 

 bark, C. micrantha, G. nitida and C. Peruviana ; and 

 a variety of Carthageua bark, C. lanceolata. In addi- 

 tion to quinine the 0. Pitayensis specially contains 

 quinidine, the C. succirubra, oiuohonidiue, and the G. 

 nitida, G. micrantha and 0, Peruviana, fromthe Huauuco 

 region, cinchonine. Tliese alkaloids extracted from 

 the barks, are recognized by their several distinctive 

 chemical characteristics, while the barks producing 

 them are likewise distinguished by a careful scrutiny 

 of their external appearance, the lichens, etc., grow- 

 ing on them, the way in which they break, their 

 taste and odour, as well as by their microscopical 

 and chemical characters. The manner in which barks 

 break transversely, or their fracture, as it is termed, 

 depends on their anatomical structure, and affords au 

 important criterion of the quality of the bark, cellul- 

 ar tissue breaking with a short or smooth fracture, 

 woody tissue with a fibrous fracture. The best char- 

 acteristics by which barks containing much quiuine 

 may be distinguished aie the shortness of the fibres 

 which cover the transverse fracture and the facility 

 with which they may be detached, instead of being 

 flexible, and adhering as in bad barks. Thns when 

 dry Calisaya is handled a quantity of very small 

 splinters run into the skin causing much irritation, 

 and this forms one of its distinguishing marks. The 

 importance of cinchoua barks in medicine renders it 

 necessary to give some account of the manner in 

 which they are collected and dried in their native 

 forests and prepared fir exportation. The following 

 notice has been extracted, therefore, chiefly from 

 Weddell and Markham. 



The hardships of bark collecting in the primeval 

 forests of South America are of the severest kind, 

 and undergone only by the half-civilized Indians and 

 people of mixed race, in the way of speculators or 

 companies located in the towns. Those who are en- 

 gaged in the business, especially the collectors them- 

 selves, are called Caicarilleros, trom the Spanish word 

 Cascara, meaning bai-k. A mnjor-domo at the head 

 of the collectors directs the proceedings of the several 

 bands in the forests itself, where provisions, and after- 

 wards the produce, are stowed away in huts of light 

 construction. 



The cascarillero, having found his tree, has usually 

 to free its stem fiom the luxuiiant climbing and 

 parasitic plants with which it is encircled. This done 

 he begins in most cases at once to remove, at>er a 

 previous beating, the sapless layer of outer bark. 

 In order to detach the valuable inner bark, longi- 

 tudui.nl and transverse incisions are made as high as 

 can lie reached on the stem. The tree is then felled 

 and -the peeling completed. In most cases, but es- 

 pecially if previously beaten, the bark separates easily 

 from the wood. In many localities it has to be dried 

 by a tire n ade on the floor of a hut, the bark being 

 being placed on hnrdles above, which proves a service- 

 able airaiigement. In Southern Peru and Bolivia, how- 

 ever, even the thickest Calisaya bark is dried lu the sun 

 wiihout requiring the aid of a hie. The thinner bark as 

 it dries rolls up into tubes or quills, while the pi.ci s 

 strippi d from the trunks are mado to dry Hat by being 

 placed one upon another and loaded with w.ights. 'ihe 

 bark of the root was foimerly neglected, but is now in 

 seven-vl instance-s brought into the market. After dry- 

 ing, the barks are either assorted, chiefly according to 

 size, or all are packed without distinction in sacks or 

 biles. In i-onie pl«cea, the bark is even stamped, in 

 order to reduce its bulk as much as possible. The deal- 

 ers in the export towns enclose the baik in nerons of raw 

 bullock hide, which, contracting as it dries, tightly coni- 

 presses the contents ed' the package (100 lbs. or more). 



Th" ports to which Iwrk is conveyed for shipment to 

 Europe are not very numerous. Guayaquil, on the Paci 

 lie Ccast. is the most important for produce of Ecuador' 



