642 



THE TROPICAL AGRICULTURIST. 



[Mafch 1, 1S84 



accords with the principles laid down by "J. B." But 

 more than this, they prove that Clerihew understood a 

 system of drying far and beyond the conceptions of our- 

 selves, if 1 may judge from my own ideas and from the 

 ideas of those I have consulted. 



Of all substances to dry, nothing comes up, for sheer 

 difficulty, to cocoa. Place it wet in a close room at a 

 temperature of 160 ° , and the cocoa will mildew (I now 

 believe from the steam it will produce) in about five hours. 

 Draw or exhaust the air upwards, and the result will be 

 the same. E.xhaust from the bottom, at the rate of a 

 fresh atmosphere, every two minutes, and you will, with a 

 temperature of 110 ° , safely dry your cocoa. 



1 have come to the conclusion that the chief aim in 

 drying is to distribute the dry ah: as much as possible, 

 and ou no account to allow it to escape until it has, to 

 its utmost, done its work ; and, as far as I can see, this 

 can only be accomplished effectually by the rapidity with 

 which it is wafted away by the fan. The moisture must 

 be evolved, not only from the material, but from the 

 chamber. 



All attempts to dry cocoa by allowing the heated air 

 to rise vertically through it have failed. First, economic- 

 ally, as the heat is so much wasted ; and second, its effect 

 is not as even as if the heated air were drawn through 

 it and exhausted from beneath. Furthermore, the results 

 of drying from heated an- rising through the cocoa have 

 not been satisfactory. The cocoa has been overdone on 

 the lower side aud unsufficiently dried upon the upper, result- 

 ing in a very inferior sample. 



I'he great principle cocoa planters have discovered in 

 drying cocoa is that all cocoa-Ulerihews should be worked 

 with the strongest fan power, but the lowest possible 

 temperature. The heat may injure the produce, the draught 

 can do it no harm. Personally, I am contented with the 

 chamber being from 110 ° to 120 ° Fur. ; but the fans must 

 exhaust the room every two minutes. 



Instead of thinking that t'lcrihew's system is falling 

 into disuse, I may say that I have listened to others 

 and carried out their views, but always without success, 

 and it is only by means of Clerihew-pipes, Clerihew-fans, 

 and the Clerihew-store that I have been able to make 

 head- way against cocoa curing. 



At first I should have written as 3Ir. Cameron does, for 

 I did more: T acted as he suggests, and have been a loser 

 thereby. These experiments nave cost me time and money, 

 while had I been contented with the old recognized .system, 

 I shonlil now Ire a rii:her man. 



A summary of the Clerihew-system as I understand it 

 is — 1st, an exposure of the produce to the heated air; 

 i!nd, the heated air to be retained with the produce for 

 a sufficient time to take up its greatest quantity of moist- 

 ure ; 3rd, this being accomplished the vitiated air should 

 be removed as quickly as possible. Now, it will, I think 

 appear clear that there is a loss in the heat being itrmm 

 upwards, when it might escape too quickly, which is not 

 the case when it is tlrawn down. 



In a Clerihew-store, comparatively drawing up heated 

 air with the same force as drawing it down, the result 

 will not be equal to 50 per cent in practical drying, and 

 if persisted in the heat must be double in quantity and 

 firewood in proi>ortion to produce the same drying effect, 

 and such heat would result in scorching the lower side 

 of the substance dried. T\'ith the same heat as in Cleri- 

 hew's .system as would dry cocoa, when the heated air 

 is drawn up, the cocoa mildews. 



I think Sir. Vollar. of Pallekelle, will bear me out in 

 all I say as regards drying cocoa. 



TJpon drjing tea I cannot think differently than that a 

 principle of drying adopted to one can be economically 

 applied to the other; so I should prefer '"Kinmond's" 

 dryer to the " Sirocco." as I know the principle of the 

 former is more like Clerihew's system — iudeed I see little 

 difference. 



The information I now give is entirely practical, after 

 much personal research, aud I may say some manual 

 labour. — W. F. L. — Local " Times." 



Watermelon Sviut. — It is claimed that a svrup can be 

 made from the watermelon finer than that from sorghum 

 or even the 'West Inilian sugarcane. 'What is needed is 

 a method of cryetallieing the syrup.— New 'i'ork Hour. 



THE EUCALYPTU.S IN SOUTHERN EUKOPE. 



Not greatly inferior in importance to the introduction 

 of the Cinchona into India aud certain of our colonies 

 has been the diffusion of various species of Eucalyptus 

 throughout our Colonies and in the South of Europe. In 

 this island the species are too tender to be anything more 

 than curiosities, though B. Guunii surrives the unfavour- 

 able conditions of a Kew winter, and E. coccifera has 

 I formed a good-sized tree at I'owderham Castle, Devonshire, 

 ' aud has even flowered (see vol. siii, p. 395). But it is to 

 oiu' colonies that the cultivation of these trees is a matter 

 of importance, and it may. therefore, be not inappropriate 

 to call the attention of om- readers to a valuable memoir 

 ou the species of Eucalyptus introduced into the Medicer- 

 raiiean region, recently pubUshed by M. Kaudiu in the 

 Annales des Sciences JVatiirelles. 'We have frequently had 

 occasion to allude to the splendid monograph in com-se of 

 I)ubUcation by Baron vou Mueller which must serve as 

 the standard of scientific information on these trees for 

 years to come. M. Naudin's object is more restricted; 

 he confines himself to the species iutroduced into Europe, 

 and he studies them from a cultivator's point of view, 

 not from dried specimens or trees m one stage of growth 

 only, but from the germination to the ripening of the fruit. 

 The rich collections of the \'illa Thuret and other gai-dens 

 along the Einera have aiforded him the means of douig 

 this. AVe have then in the treatise before us one of those 

 botano-horticultm'al memoii-s which are of such special 

 value to cultivators. 



Oue of the first points noticed is the variation in the 

 form of the leaf in the same plant, which is so marked 

 a feature in the species best Imown in this coimtry, E. 

 globulus. 31. Naudin points out how the seedlhig plants 

 of various species differ one from another in this part- 

 icular. If the trees are pollarded, shoots are produced 

 from ne.ar the base of the tiunk, bearing leaves similar 

 to those of the juvenile plant, and leaves of this form 

 are often produced without any injury to the tree having 

 taken place. This partial reversion to a previous con- 

 dition is no bar to the production of blossom, as flowers 

 aud fruit are produced on these juvenile looking >':oots 

 as well as ou those of the adult branches. AAe Lave, 

 then, in the Eucalypti the same condition th f. occurs 

 in so many Conifers, Thuias, Junipers, kc, ar.l to which 

 we owe many of the Ketmospoias of our gardens. lu 

 the latter class of plants the disposition of the breath- 

 ing pores, and the production of the leaves on branches 

 of different character of growth, pomt to a difference of 

 function, which is not hinted at by M. Naudin in the case 

 of the Eucalyptit^ although he suggests the possibility of 

 the diversity in form having been due to cross or hybrid 

 fertilisation. 



M. Naudin passes in review the " characters " that have 

 been proposed to distinguish the species, such as the form 

 and nervation of the leaf, the size and habit of the tree, 

 some being small, others furnishing trees which exceed 

 the famous Sequoias of California in height. The char- 

 acters afforded by the bark of the full-gromi trees, such 

 as are recognised by the foresters, and which have been 

 adopted by Baron von Mueller are also noted ; but for 

 his purposes M. Naudin prefers characters taken from the 

 inflortscence, flowers, and fruit. Singularly enough it is 

 not yet ascertained whether fertihsation takes place before 

 or after the fall of the Uttle caj) which at first covers 

 over the stamens and styles. If before, then cross-fertihs- 

 ation would not occur as a rule. JI. Naudin, however, 

 suspects that the fertihsation takes place after the fall of 

 the cap, and that much of the variation met with is due 

 to crossed impregnation. This would certainly seem the 

 most probable riew, though against it we have to set the 

 opinion of Baron vou Mueller, whose experience is so 

 large that no one would be disposed to question it unless 

 he felt very secm-e of his facts. So far as the Kiviera 

 is concerned, and the few species there grown, the question 

 as to the self or cross-fertilisation sm-ely could speedily 

 be settled, even if it were more difficult to prove actual 

 hybridity. 



As to propagation, M. Naudin recommends seeds in pre. 

 ference to cuttings, there being no difficulty in raising 

 the seed in seed-pans imder glass in a warm greenhouse 

 or propagating pit. As the seeds are very small the 

 should be covered with only the slightest possible coveriu 



