i3S 



THE TROPICAL AGRICULTURIST. 



[September i, 1882. 



eparation be conducted simultaneously %vith the determin- 

 ation of the crystallized quinine sulphate in another portion, 

 the whole analysis can Ije completed in about six hours. 



The mixed alkaloids of yellow cinchona bark consist almost 

 wholly of quinine, and hence the portion soluble in ether 

 represents the whole useful constituents of the bark. 

 Pale and red barks, on the other hand, contain a consider- 

 able proportion of alkaloids insoluble or sparingly soluble 

 in ether. Hence the use of chloroform in the general 

 process for assaying cinchona barks (see page 448). 



In some cases the alkaloids soluble in ether are con- 

 taminated to a considerable extent with colouring matter. 

 In this event, the following is a good method of obta-in 

 ing colourless qiunine sulphate : — The ether-residue is 

 di-ied thorougUy and weighed. It is then dissolved in 

 30 c.c. of absolute alcohol, and decinormal sulj^huric acid 

 cautiously added from a burette, using litmus paper as an 

 indicator, till the hquid is neutral or veri/ faintly acid. The 

 measure of acid used is' noted. Each c.c. is equivalent to 

 ■324 grammes of anhydrous alkaloids. The liquid is next 

 evaporated nearly to dryness, and a measm*e of decinormal 

 sulphxiric acid added equal to that previously required for 

 neutralization. 30 c c. of hot water are added, and the 

 liquid boiled tiU complete solution results. Purified animal 

 charcoal (prepared as described on page 227) is added, in 

 quantity equal to the weight of the ether-residue. Heat 

 the liquid on the water-bath for 20 minutes, filter, and 

 wash the residue twice with boihng water acidulated with 

 sulphuric acid. The filtrate is brought to a concentration 

 of 70 c.c. for each 1 gramme of ether-residue taken, and 

 then cautiously neutralized with caustic soda, and further 

 treated as decribed on page 453. 



Special processes for separating certain of the cinchona 

 bases will be found on pages 435, 441, and 445, as also 

 methods for testing the purity of the various commercial 

 salts of the alkaloids. 



Ob^aously every analyst of cinchona bark or other 

 substances ought to possess Mr. Allen's very full and 

 able work. 



THE CULTIVATION OF CINCHONA IN 



CEYLON. 

 We are indebted to the courtesy of Dr. Tiimen, 

 the Director of the Eoyal Botanic Gardens in Cfylou, 

 for a copy of his report on the work carried out 

 under his guidance in the gardens during the past 

 year, and are thus enabled to place before our readers 

 some interesting information as to the progress of 

 the attempts to cultivate in Ceylon various economic 

 and useful plants, among which cinchonas aud rubber- 

 yielding plants are, perhaps, the moat important at 

 tbe prest-nt time. As regards the cinchonas, it may 

 be mentioned that during the year 1S80 a very great 

 impulse was given to their cultivation in Ceylon, and 

 A'erv sanguine anticipations were entertained as to the 

 probable results of this epterijrze. The varieties grown 

 were ijrinoipally C officinalis and C. snccirubra. The 

 climatic conditions of the higher elevatious in Ceylon 

 are remarkably suitable for the growth of the former, 

 but at lieights below 4,500 feet it agpears more 

 desirable to grow other varieties. Dr. Trimen satislied 

 himself last year that tbe more valuable C. Ledgeriaiia, 

 though less abundant than the sorts abive-meutioned, 

 was nevertheless represented by a considerable num- 

 ber of trees scattered over several estates in ihe island, 

 these having been raised from seed obtained either 

 from the gardens of the Dutch Government in Java, or 

 from Darjeeling or the N'lgiris, but in all cases being 

 descendants of the seed originally brought over by Mr. 

 Ledger. In speaking of the cultivation of this most 

 valviable variety of cinchona, Dr. Trimi'u took occasion 

 to impress upon the attention of ownersof these trees 

 the extreme importance of minimizing the chances of 

 their being crossed by the pollen of otber and inferior 

 kinds. He recommended that, it any of these were in 

 the immediate neighbourhood, they should be destroyed, 

 and that in selecting seed trees no paina should be 

 spared in ascertaining from analyses by a competent 



chemist which were most suitable for the jjurpose, all 

 those which did not give good results on analysis of 

 the bark being ruthlessly destroyed. It is only in 

 this way that it will be possible after a fe%v years to 

 obtain seed that will come true, and growers nity 

 judge of the desirability of this course beiug adopted 

 by them from the probability that before long it will 

 be only the best kinds of bark yielding a large amount 

 of quinine that will secure good prices. 



In the report for the year 1881, which has just 

 come to hand, Dr. Trimen again refers to the supreme 

 importance uf selection based on analysis in the scienti- 

 fic cultivation of C. if (7(;i« ■;■;«««, and he mentions that 

 the observations made on this point in his previous 

 report have been supported by farther experience. Aa 

 a general rule the botanical characteristics were found 

 to tally with tbe bark value, so that selection intellig- 

 ently made on that basis was usually justilied by 

 subsequent analysis ; but such very distinct exceptions 

 to this general rule were occasionally met with as to 

 force one to the conviction thattheproduclion of alkaloids 

 must be largely personal, so to speak, to the partic- 

 ular tree, apurt from its inherited external characters. 

 For this reason, therefore, Dr. Trimen considers that 

 analysis must still be regarded as the only certain 

 guide in the judicious seiectiou of trees for the cult- 

 ivation of O. Ledgeriana. 



The simple process of grafting on succirubra has been • 

 found in a large proportion of cases both easy aud 

 successful in the propagation of V. Ledijeriana, and 

 it is considered that this or some similar process must 

 become the general practice in the cultivation of 

 specially valuable trees on tlie principles advocated. 



Much attention has lately been directed to the large 

 and usually readily distinguished trees found scattered 

 over estates in Ceylon, and vari.nisly known as 

 '•hybrid," "lanosa," or "large-leaved Coudaminea." 

 These trees were sent out from the Hakgala nurseries 

 in past years, usually as succirubra, but sometimes as 

 officinalis, and they are identical with the " magni- 

 folia," " pubescens," " robus'a," etc., of the Nilgiri 

 Government plantations, from whence they were doubt- 

 less originally received. They were first noticed there 

 by Mr. Mclvor, and considered at one time by him 

 to have originated by the crossing of succirubra and 

 officinalis. The samo view was aiso taken in Ceylon, 

 but Colonel Beddome, after examiniug these plant- 

 ations, has come to the conclusion that the trees in 

 question are not of hybrid origin, but from a well- 

 marked aud dittinpt species. Dr. Trimen does not 

 share this view, which was largely based upon the 

 positive statement of Mr. Cross that the plant is the 

 same as that yielding the " Pata de Gallinazo" bark 

 of Chimborazo, which he collected there when with 

 Dr. Spruce, and he considers that there are great 

 dilBculties in accepting this story. Thus, for instance, 

 a comparison of the Nilgiri pl.mt with Spruce's 

 original specimens at Kew does not lend it any 

 support whatever. On the contrary, the two kinds 

 seem to be quite di.stinct in several respects, and 

 M. Triana, one of the most careful and accurate 

 botanists who has made cinchonas a special study, 

 has referred Spruce's specimens to C. erythranlha, 

 Pav., which is considered to be a variety of V. 

 2nibescens, Vahl. According to Dr. Trimen, the view 

 which is on the whole most in accordance with the 

 facts is that the plant is a hybrid which has acquired 

 some permanence and stability, though he is not in 

 a position to speak decisively as to the amount of 

 permanence from seed. Colouol Beddome maintains 

 that it comes as true to type as any other species, 

 while the majority of 'observers in Ceylon state posit- 

 ively that a lar^e proportion turn out to be sued- 

 ridirn and officimiUs. In ^ikkim, also, where this kind, 

 ■originally from Ceylon, is called " ignota," lullyhalf 

 the seedlings are said to come up officinaUi. Dr. 



