December i, 1884.] THE TROPICAL AGRICULTURIST. 



497 



into the air above its point of saturation. Or if the 

 wet cloth were put una heated stove or held before a 

 fire, all the moisture in the cloth would be dispelled 

 from it in visible vapour, the air around it is rilled 

 with vapour beyond saturation. Suppose again we 

 have very dry air, i.e., air very far below saturation. 

 This may be the case either by heating the air or 

 by taking out of it its moisture by some chemical means. 

 In either case, if a wet substance, such as a sponge, 

 were put into this dry air ; the moisture in the sponge 

 would pass rapidly and imperceptibly into the air, 

 till it was at or near saturation. In the process of 

 changing into vapour the moisture would take heat from 

 the sponge and leave it cold. So ia it with a porous 

 gnglet of water when exposed to the action of dry 

 air. Tho water oozing through the gnglet evaporates 

 imperceptibly and so cools the goglet and the water in 

 it. The wet bulb thermometer is another example of 

 the same thing. The liiior the air .he more rapid the 

 drying or evaporation of the moisture on the bulb 

 and the cooler it becomes. Now drying cocoa in the 

 sun is an instance of the former mode, and drying 

 it in dry air an instance of the latter. Let ub suppose 

 the average temperature of the air in the two cases is 

 70° and the wet bulb 5° lower. The cocoa exposed to 

 the sun receives this direct radiated heat and is 

 warmed up to a temperature of 120°. This temperature 

 prevailing in the interior of the " nib " as well as on 

 the surface. This heat, like the case of the wet cloth, 

 sends off vapour into the air even beyond the point 

 of saturation so as, it may be, to be visible. Aud the 

 vaporizing will take place in the centre of the nib, 

 a9 well as on the surface. Consequently the nib will be 

 dried pretty equally all through. 



By the heated air process, the air is warmed up to 

 120° suppose. This makes the air dry. If we 

 suppose 65° to be still the point of saturation, then 

 the air at 120° will have 55° of dryness. The re-ult 

 is, that the moisture on the surface of the nib passes 

 rapidly into the dry air, while the interior of the nib 

 has to part with its heat in the process, and gets 

 cooled down towards 65°. That it will not reach 65" is 

 probable. Perhaps " W. F. L." or some of the Dumbara 

 savants might favour us with the result of a test of 

 the two by gathering a quarter bushel of nibs from 

 the barhacue, aud another from the clerihew and after 

 a few minutes to allow the centres and surfaces of the 

 nibs to arrive at a uniform temperature, insert the 

 thermometer into each heap. If I am correct, I would 

 expect that, supposing the heat of the sun on the 

 barbacue and that of the air in the Clerihew were the 

 same. 120°, the heat of the sun-drifd nibs would be 

 higher than that of the air-dried. It would be inter- 

 esting and pei haps instructive also to have the 

 difference at the beginning, middle and end of each 

 of these two processes. 



If I am right about the difference of tempera'ure, 

 it becomes a question how far th. se two different 

 temperatures affect the fermentation of the cocoa. A'so 

 if ine air dries the outer surfnce quicker than tho 

 interior of the nibs, the outside would be dry while 

 the interior was damp and as the outer surface got 

 dry, the moisture would pass slowly from the inteiior, 

 and if the cocoa were removed from the Clerihew in 

 this stage, the interior moisture would be apt to 

 spread itself through tbe whole, making it all to some 

 extent damp and this also might possibly affect the 

 fermentation. 



If such is found to be the ca3e, the heated air pro- 

 cess might be amended by having the cocoa contiguous 

 to a heated surface, which radiates heat into it, as 

 the sun does and so the process of drying by heat 

 might go on simultaneously with the dry air process. 

 Let us hear what the savants of Dumbara and Matale 

 have to say in the matter. — Yours, J. B. 



63 



CACAO PODS FROM THE PERADEN1YA 

 GARDENS. 



Sir, — Dr. Trimen may be perfectly correct in say- 

 ing that the cacao seed in question "was quite ripe 

 enough for planting," but it does not follow that the 

 purchaser of said seed having tine young seedlings, is 

 proof of its having been ripe seed — we all know to 

 our cost that seedlings don't mean plants, and plants 

 don't mean trees. I quite agree with Mr. Hollow ay 

 that great care is necessary in picking ripe pods for 

 seed, or even for curing and export. A London broken 

 can tell at once whether the pods have been picked 

 unripe or otherwise. So can some of our Colombo 

 storekeepers, who, I daro say, have never picked or 

 cured a bean of cacao in their lives. Dr. Trimen, I 

 dare say, can teach us a good deal, but when it comes 

 to a simple question of a ripe cacao pod, coffee berry 

 or cardamom capsule, I fane}' we have little to learn 

 from him.— Yours fai'hfully, ANDRKW POLSON. 



NO. II. 



Maria. 22ud Nov. 1S84. 



Dear Sir, — With reference to Dr. Trimcu's letter 

 of 19th inst. in the Observer of 20th inst., and his 

 uncalled-fi r n marks, I have to ask Dr. Trimen the fol- 

 lowing questions : — (1) Did he (Dr. Trimen) sr e the pods 

 referred lo? (2) H w does he know a ripe cacao pod ? 

 (3) Is it, or is it not. the fact that when you shake 

 the pod you will hear the seed shake inside of the pod ? 

 When you scrape awaj' the light surface-skin of the 

 pod, if ripe, you will find it yellow (not green) under- 

 neath — tins at least was the test I was told to use 

 by the. late Dr. Thwaites when I bought pods from 

 the Gardens and have used ever since when I gather 

 pods for sale or cuiing and such I do know is the 

 test by all cacao planters. Now in the case referred 

 to by me, I took the four pods ; tested and examined 

 them one by one ; found on removing surface-skin 

 that it was still green underneath, and, on shaking 

 the pod, the seed did not rattle. I pronounced them 

 not ripe enough to plant, and passed them on to 

 several gentlemen and natives present for examining, 

 so there was no mistake. 



I am much surprized that Dr. Trimen should bring 

 forward as proof that the pods were ripe, Because the 

 owner reports that the seed has grown into line young 

 seedlings. There are many planters iu Cej Ion v> ho can 

 tell Dr. Trimen of the waste of money and time lost t y 

 them by having purchased unripe c'nc im, tea, 

 cardamom and other seed ; the seed did grow into 

 nice seeellings, but how soon did they die afterwards 

 or remain seedy plants and had to be pulletl out. 

 By Dr. Trimen's letter, he was aware of these four 

 pods, of new variety of cacao pods, being sold to one 

 man (a rich native); will he now say why Enrnp an 

 planters who have applied for pods of the new varieties 

 have been told — so I am informeil on go> d aulhoiity — 

 they coulel have plants at twenty five cents each, 

 but no pods were sold, yet this man got four pods at 

 twenty-five cents each? Great care should be taken 

 at the Gardens t» do justice to all orders — ripe seen, 

 healthy plants and distribution of new products. If 

 the test described by me is the correct one, my 

 statement was not false, neither impertinent, but In. 

 Trimen's letter was out of place aid his rrma ks 

 uncalled-for.— Yours faithfully, J. HOLLOWAY. 



Royal Botanic Gerdens, 26th Nov. 1SS4. 

 Sir, — Your rorrevprndent Mr. ndloway thinks fit 

 to persist in his erroneous statement, af'cr my <le- 

 libenite contradietou of it, and attempts to su; pert 

 it by a fallacy. 1 he tests he employed are of 

 course well-known to indicate ripeness in the c.-seof 

 the ordinary cultivated "Ceylon" cacao, but they 

 are inapplicable to the varieties to which the pods 



