September i, 1SS3.] 



THE TROPICAL AGRICULTURIST. 



171 



Cinchona Bark Harvesting. — Haputale, July 29th. — The 

 following extract from a letter of a planter in this district, 

 who, from his lengthened experience and abiUty, is well able 

 to speak with authority, is of great interest, particularly 

 wth regard to what he tells us of the poor results in renewed 

 bark obtained from very old suocirubra trees as compared 

 with officinalis:— -'As regards disease in the pith of cinchonas, 

 I am coustantly finding it in the finest of my hybrids; trees 

 that look perfectly healthy are infected with this discolor- 

 ation, well developed, too. of a dark Ijrowu colour. On ex- 

 amining a dead tree the other day, I found canker at the 

 collar, but the pith of thi' branches showed no discoloration. 

 njy tlie way. I f omul a yrmng officinalis tree covered with what 

 looked like white bug's. The stem and the branches were 

 simply covered mtl i this bug. like scales. I have found by e-v- 

 perience that condamiuea officinalis, 12 years old, renews 

 better than succirubra of the same age. I give yon the 

 figures:— 145 succirubra trees gave in August, 18S2, l,()021b. 

 original wet bark, and KiS of the same trees jielded l.OlCilb. 

 of renewed wet bark in March 1883, or 65 per cent, on 

 original harvest ; whilst 12.3 officinalis trees in August. 1SS2, 

 gave 444tb. of original wet bark, the same trees yielded 

 in March, 1SS3, 3t)71b.of renewed wet b.ark. or 82 per cent, 

 on original harvest. Ten of the succirubra trees were not 

 shaved at aU as they had renewed very slightly. I prefer 

 the term original bark to natural bark, as all barks are 

 natural, whether renewed or otherwise. To show that 

 young succirubra renews well, I send the following: — 5.400 

 trees succirubra planted in December, 1878, gave in July, 

 1882, 8471b. of original wet bark. In February, 1883, 

 1.519 lb. of renewed wet baik were harvested from the 

 same trees — an increase of nearly 100 per cent. — "Times 

 of Ceylon." 



How Tlants fiROW. — In the practical view of the subject 

 the nutrition of plants is a matter of the greate.st importance. 

 It underlies the whole business of plant production for 

 economic purposes, and illustrates the near relation of the 

 chemist to the manufacturer. Here is a grave question : 

 How do plants obtain their carbon? AVhcn the water and 

 g<aso.s h.ave been expelled from a plant by heat what re- 

 mains consists of carbon to the amount of about 50 per 

 cent. It follows that the living plant does a lai-ge trade 

 in the article, and a hasty e^^Jlanation might be found in the 

 assertion that plants obtain their carbon from the soil. Hut 

 Dr. Masters does not favour this view. He says: "This 

 large amount of carbon has to be taken up in the form 

 of carbonic acid by the leaves. It is a moot point whether 

 any carbon is taken up by the roots, but, it any, it is only 

 a .small proportion. In any given volume or quantity of air 

 the proportion of carbon is very minute, so that the leaves 

 must be very active in securing and utiUsing all that comes 

 within their reach." That plants obtain carbon by the aid 

 of their- leaves almost exclusively is one of the first pro- 

 positions of Liebig in his "Chemistry of Agriculture," and 

 it is made evident Ijy experiments in manuring that to 

 supply carbon directly to the roots of plants is a waste of 

 power. Having this knowledge, we turn the functions of 

 the leaf and consider once again the uses of air and light 

 to plants. It is by the agency of the green colouring mat- 

 ter, when exposed to the action of light, that the leaf is 

 en.abled to decompose the carbonic acid of the atmosphere; 

 retaining the carbon hi aid of its own structure and liberating 

 the oxygen for the advantage of animal life. And of necessity 

 we must inquire into the nature of the chlorophyll, for it 

 is compounded for the most part of carbon, with small 

 proportions that of oxygen, hydrogen, and nitrogen. It 

 is by the agency of chlorophyll that glucose and starch are 

 formed, and light is absolutely essential to the process. 

 The case of parasitic plants illustrates in a curious manner 

 the usees of chlorophyll. The broom rapes and dodders are 

 destitute of chlorophyll, and yet they cannot live without it. 

 How then do they overcome or evade the impossibility? 

 They attach themselves to other plants and rob them of 

 the elaborated secretions that their chlorophyll has contri- 

 buted to produce, just as a man without an income may 

 contrive to live by tliieving. But the mistletoe presents a 

 curious case, for it has its share of chlorophyll and yet 

 disdains to dig for its bread by putting its roots in the 

 earth. The case of the mistletoe is full of suggestion to the 

 man whose business it is to make plants grow, for the 

 chemistry of this ])arasite explains its pi'edaceous character. 

 An apple tree can obtain from the soil only so much po- 



tash and phosphoric acid, and a mistltoe probably could do 

 no more if similarly circumstanced. But then "so much'* 

 will not satisfy the parasite; it requires twice as much 

 potash and five times as much phosphoric acid in. pro- 

 portion to bulk as the apple tree. Therefore, . instead of 

 beginning with water and clay as the apple tree does, 

 it begins by absorbing elaborated vegetable juices from the 

 tree that fosters it, and alwaj-s, however slightly and 

 slowly tends to the destruction of that tree. — Garikncn 

 jTIar/aziiie. ' 



A New Substitute for Coffee and Cocoa. — The kola 

 nut. which has cbiimed attention from time to time as a 

 remarkable stiniubint. rivalling the celebrated coca leaves 

 as a means of sustaining long periods of fast and severe 

 exertion, now comes forward in a new character. Dr. Neish, 

 of Port Royal, Jamaica, reports that the value of these 

 nuts is enhanced by the fact that citrate of caffeine — a 

 medicine now much employed for the relief of sea-.sickness, 

 megrim, and other nervous complaints — can be readily 

 obtained from then:, furthe reason that they actually con- 

 tain more caffeine than coffee berries. Another advantage 

 is th<at in the kola nut the caffeine is in the free or un- 

 combined state. These nuts seem therefore likely to take 

 their place in the market as furnishing a nutritive and 

 stimulant beverage. Besides being rich in the active prin- 

 ciple of coffee, and containing also a large projiortion of 

 the obromine, the active principle of cacao, these nuts, in 

 addition, contain throe times the percentage of starch con- 

 tained in chocolate ; and, moreover, they also contain less 

 fat, so that, in addition to stimulant and nutritive proper- 

 ties, there is the probability that a chocolate prepared from 

 them will more readily agree with delicate stomachs. Mr. 

 D. Morris warmly supports Dr. Neish 's suggestion as a very 

 app ropriate one. Both the cacao and kola belong to the 

 same natural order, Stei'cidiacar, and the habits and char- 

 acteristics of the two trees are very similar. They both 

 effect low warm situations, and, in view of the probable 

 demand for kola nuts, attention might very well be given 

 to their cultivation. The tree is already cultivated to .a 

 considerable extent in .Jamaica, where it is known under 

 the name of byssi, and its nuts seem likely to become quite 

 a valuable product. — Colonita (did Jndta. 



Longevity of Trees. — How vast are the periods of lief 

 alloted to the longeval trees may be judged from the 

 following list of ages known to have been reached by 

 patriarchs of the respective kinds: — 



Elm 300 year.s. 



Ivy 335 „ 



Slaple 516 „ 



Larch 576 ,, 



Orange 630 „ 



Cypress 800 „ 



Olive 800 „ 



Walnut !)00 „ 



Oriental Plane 1,000 „ 



Lime 1,100 „ 



Spruce 1,200 „ 



Oak 1,500 „ 



Cedar 2,000 „ 



Yew 3,200 „ 



The way in which the ages of these vegetable Nestors 

 have been ascertained leaves no doubt of their correctness. 

 In some few cases tlu- data have been furnished by his- 

 torical records, and by tradition ; but the botauic.al archa>o- 

 logist has a resource independent of either, and, when care- 

 Ifidly used, infallible. ... Of all the forms of nature 

 trees alone disclose their .ages candidly and freely. In the 

 stems of trees which have branches and leaves with netted 

 vein.s — that is to say, in all exogens — the increase takes 

 place by means of an annual deposit of wood, spread in 

 and even layer upon the the surface of the preceding one. 

 In the earlier periods of life, trees increase much faster 

 than when adult — the Oak. for instance, grows most rapiiUy 

 between the twenieth and thirtieth ye:u's, and when olil the 

 annual depo.sits considerably diminish, so that the strata 

 are thinner and the rings proportionately closer. Some 

 trees .slacken in r.ate of growth at a very early jieriod of 

 life: the layers of the Oak. become thinner after forty; 

 those of the Elm. after fifty; those of the Vew, after 

 sixty. — Leo. 11. Guindon. — Joi'rmd of Forestri/. 



