Dec. I, 1886,] 



THE TROPICAL AGRICULTURIST. 



3^g 



Thus it is seen that by renewing a six year old tree, 

 00 per cent more of sulphate of quinine is obtained, and 

 by working on a twelve year old tree only an increase 

 of 12 per cent takes place during the same period of 

 two years. With regard to the total alkaloids it should 

 bea'so noticed that the shaving has made an increase 

 cf 39 per cent in t^e younger tree, while the older bark 

 has somew'iat deteiiorated. One of the most import- 

 ant features in these results is that tlie renewed bark 

 from the six yeir old tree is superior to the natural 

 bark from trees of twice the age. 



I have had very few opportunities of observing the 

 effect of shaving on pure Ledger barks, contaning little^ 

 if any, alkaloid, besides quinine; but it appears that 

 hybrid Ledgers of the broad leaved variety, holding 

 cinchonine, are capable of great improvement by the 

 shaving process, as the following renewals of eh ven 

 months will show compared with the natural bark of 

 six year old trees. 



/^^'P.^- Total. 



Ledger, narrow leaf, natural, 1885 4 09 5f)7 



„ „ renewed, 1886 662 8-49 



Ledger, broad leaf, natural, 1885 290 601 



„ „ renewed, 1886 5-19 8-Jl 



The sulphate of quinine in the narrow-leaved Led- 

 ger had increased 62 per cent, and in the broad-leaved 

 Ledger 79 per cent ; the greater increase in the latter 

 var'©ty is due to the presence of other alkaloids which 

 appear to develop quinine in the growth of the tree. 

 Shaving old trees has certainly not had a beneficial 

 effect in some trials made on Cloven ment estates. 

 Both officinalis and succirubra trees from sixteen to 

 twenty-one years of age cannot well bear the re- 

 moval of the bark in this way; the renewal takes 

 place slowly, and is found to be impoverished instead 

 of enriched. An officinalis on Dotabetta of twenty 

 years' growth was shaved ; the shavings gave 3 '66 

 per cent sulphate of quinine. After six months some 

 renewed shavings were taken and found to yield only 

 1-85 per cent; the bark was then commencing to 

 decay, and the tree has since died. 



Experiemcnts in 3f(iniirinf/ Cinchonas. — The effect of 

 manuring c'nchona trees in order to stimulate their 

 growth and produce a greater yield of alkaloids has 

 recently been tried at Naduvatam. The first experi- 

 ment was made upon a succirubra of seven years' 

 growth. Cattle manure, which had been previously 

 kept for some time in closed pits, was applied some 

 six months before the bark was taken for analysis. 

 A sample of bark from a tree iu the sume plot, but 

 which had not been manured, was collected at the 

 same time for comparison. Two samples of magni- 

 folia bark were taken from trees which had been 

 manured in a similar manner to the succirubra ; the 

 first was seventeen years, the second twenty years 

 old, and simples from utmanured trees were taken for 

 comparative analysis at the same time. The results 

 of the ex: minations are tabulated on the next page. 



Amor- 

 Cin- Cin- phous „ . 1 

 Qui. choni- cho- Alka- ■'^'"^^'• 

 nine. dine. nine, loids. 

 SucciruVra manured 2-29 3-78 1-94 -52 8-53 

 „ unmanured ISl 413 2-03 32 7-99 

 Mag'folia.l manured 378 390 -28 -82 8 78 

 „ „unm'red 3-13 439 -56 -39 8'47 

 „ 2 manured 2-59 349 1-21 -52 7 82 

 „ „unm'red 2-62 2-67 '67 "56 6-52 

 It will be seen that the manuring has had the effect of 

 increasing, in each instance, the amount of total 

 alkaloids in the bark ; and the quinine— the most 

 important feature — has received a gain of 52) per cent 

 in the succirubra, and 20 per cent in the first mag- 

 nifolia. In the older magnifolia bark the quinine re- 

 mains about the same in quantity, and if no other 

 influence is at work it might be inferred that older 

 trees are not so sensitive to the action of manure 

 as younger and more vigorous growing trees which 

 have not reached maturity. The food of such plants 

 as cinchonas, which yield alkaloids in large quantitj', 

 must of necessity contain some nitrogenous element, 

 »nd as this must be t^ken from the ground it is only 



fitting that a manure of this kind, which contains 

 some constituents that are .similar in their nature to 

 alkaloids, should be supplied periodically to the soil, 

 llegarding the question from a commercial aspect, 

 the higher value would cover the expense of the 

 manure and the cost of its application to the land 

 The succirubra bark mentioned in the. first experi 

 ment, if the unit were 4d., wouM realize in the mar 

 ket S(?., per pound, whereas the bark of the manured 

 tree would be worth more than l.<t. per pound. I 

 believe the effect of manuring would be more ap- 

 parent in crown and Ledger barks, with large pro- 

 portions of quinine in the total alkaloids; in such 

 rases, the extra outlay on manurial agents, compared 

 with the additional value of the lark, would be much 

 more remunerative. 



J/icrcase of AUailoiih with the Age of trees.— A. 

 question of much importance in cinchona cultivation 

 is the age to which trees should grow before the 

 bark can be profitably taken. To settle such an 

 inquiry a large number of analyses of barks taken 

 from trees of all ages should be available. In the 

 following tables I have made a selection of both Ledger 

 and red barks, and have arranged them according to 

 age. Some of the figures are averages of two or more 

 analyses, and as the two lists represent some forty 

 sam.ples, I hope they will help to throw some light 

 on the subject. 



The first list comprises natural barks of the narrow 

 leaved variety of C. Ledgeriana, and, with one excep- 

 tion, they all came from the Wynaad district. 



The second list is made by taking from my 

 laboratory journal all those red barks whose ages have 

 been determined, whether they came from the 

 Government Plantations at Naduvatam, or from jjrivnte 

 estates in Wynaad, Ooorg or Travancore. 



Other 



Alka- Total, 

 loids. 



277 511 



2-61) 5-52 



2-90 682 



181 7-46 



1-78 7-54 



1-46 7-05 



•55 0-70 



1-15 900 



■88 816 



1-00 815 



1-45 10-20 



•85 7-67 



In the Ledger barks it will be noticed that there is a 

 steady rise of quinine up to the age of between five and 

 six years, after which there is no apparent increase. 



In the second table of red barks the same fact is 

 shown, that the bark has attained its maximum con- 

 tent of alkaloid when between five and six years of 

 age. The quiuine increases up to twelve years, but, 

 as pointed out before, the renewed barks of the 

 younger trees much exceed the slightly increased value 

 of these older barks. The trees of .sixteen and twenty 

 years show a marked deterioration in alkaloids, al- 

 though the bark is often in large thick fibrous pieces, 

 similar to the drug that was originally exported from 

 the South American forests. 



Amor- Total. 

 Red barks. Qui- Cincho- Cincho- phous 



nine- nidine. nine. Alka- 

 loids. 



2 years "55 72 120 122 369 



3 „ -85 175 167 -99 5-26 



3i , 108 1-65 1-15 -61, 4-52 



4" „ 113 203 1-79 -58 553 



4.1 „ 1-02 2-64 178 -50 5'9I. 



5 „ 1-23 272 2-36 -52 6-83 



5| „ 1-32 215 3-11 -63 721 



(ih , 1-31 3-22 218 71 7-42 



7" „ 170 2-69 228 -93 7-60 



7h „ 178 3-18 1-97 -53 7-46 



12" „ 1-81 2-62 208 -90 7-41 



10 „ 1-08 -94 1-04 1-57 4-03 



20 78 113 1-37 :97 425 



