April 2, 1883.] 



THE TROPICAL AGRICULTURIST. 



779 



and, consequently, I should recommend pi-oprietors of 

 high lying estates to wait until they see a crop upon 

 theii- trees before manuring. Lastly, that to keep 

 coffee in good heart it is necessary to manure it, if 

 bearing crop, every year. 



Many of these views only bear out previous re- 

 commendations of Mr. Hughes', and those who believe 

 in cultivation should study his manual : at the same 

 time, they will be always welcome to such inform- 

 ation as I am able to give from my own experience 

 on making personal application. — Yours faithfully, 

 W. D. BOSANQUET. 



[The advice given to proprietors of elevated lands 

 not to manure until theii- trees shew signs of bearing 

 crop is sound and practical ; and we fear owners of 

 low places will, for some time, at least, follow the 

 same course. Although we have heard of manure 

 telling very favourably, either at once or years after 

 it has been applied, in counteracting leaf-disease and 

 producing crop, yet there is much mournful evidence 

 of the truth of Mr. Marshall Ward's statement that 

 in many cases (including those of estates which had 

 been steadily and libei'ally cultivated) the application 

 of manure merely led to fresh supplies of leaves for 

 hemileia vastatrix to feed upon, instead of the de- 

 siderated fruit. Happy those who can afford to manure 

 when the promise of fruit comes, as we hope it soon 

 will, simultaneously with the disappearance of, per- 

 haps, the worst pest which has ever visited coflFee, 

 since it was first cultivated. — Ed.] 



CARBOLIC ACID AND COFFEE LEAF- 

 DISEASE. 



Sir, — When Mr. Storck announced publicly that he 

 had resorted to stronger solutions of carbolic acid than 

 those he had formerly employed, most people no 

 doubt regarded this change of practice as a virtual 

 acknowledgment of the inefficaoy of the weaker solu- 

 tions first prescribed. Those who knew the properties 

 of carbolic acid, would, howevei-, at once perceive 

 that Mr. Storck must have been unacquainted with 

 those properties, or he would have known that such 

 strong solutions as he proposes are impossible. Ac- 

 cording to Mr. Ward, carbolic acid is soluble In water 

 to the extent of four per cent only, and therefore, 

 if Einy larger proportion be added, all the excess of 

 acid, above the four per cent which the water is 

 capable of dissolving, remains, like so much oil, in 

 a separate state, unmixed. Unlike oil, however, the 

 acid undissolved sinks to the bottom. 



So far as regards leaf-disease, it would hardly be 

 worth while to revive discussion of carbolic acid, 

 either as a remedy or a preventive, but carbolic acid 

 is so important an antiseptic and is so likely to be 

 efficacious in other ways than in the cure of leaf- 

 disease, that all your readers must feel under oblig- 

 ation to your correspondent who lately published 

 the result of evaporation of carbolic acid and its 

 solutions, in a recent issue of the Obfrnrrer. 



I, for one, would record my thanks for the con- 

 tribution to our knowledge. At the same time, I 

 would ask the gentleman who took such pains with 

 the experiments recorded, if he ascertained the actual 

 nature of the residuum alter evaporation had ceased ? 

 Until that is known, the experiments cannot be said 

 to settle or materially to advance, the inquiry aa to 

 the volatility or otherwise of carbolic acid. The ex- 

 periments seem to show that the vapour of the solu- 

 tion carries off a?/ the water, 3,nii prohahly something 

 more ; but the question still remains unanswered, as 

 to irhat is so carried off. It appears to be assumed 

 that, when the weight was reduced by a quantity 

 exceeding the total amount of water added to the 

 acid, the difference represented a diminution of 



the acid to the extent of the excess ; but, be'fore 

 that assumption can bS admitted, it has to be shown 

 that the residuum, after evaporation, consists of un- 

 decomposed carbolic acid. It is evident that, if you 

 have nothing but carbolic acid (phenol) and water to 

 begin with, and if nothing but water and phenol 

 pass off in vapour, nothing but water and, or, phenol 

 can remain. Now, from what I have seen of the 

 more or less dry, amorphous residuum, after evapor- 

 ation, of the mixture, I feel certain that it is not 

 phenol ! In other words, it would seem to be at least 

 probable that the evaporation, either from the first, 

 or after a certain stage, decomposes the phenol and, 

 if so, it is an open question whether any of the vapour 

 which passed off consisted of carbolic acid. It may 

 all have consisted of the vapour of water, and of 

 some component, or components, only, of the phenol. 

 Perhaps some of your scientific correspondents may 

 know what takes place during evaporation of the 

 mixture, they may possess treatises which may enable 

 them to ascertain. In either case, they would do good 

 service and confer a great obligation by imparting the 

 information so possessed. All that my scanty library 

 informs me on the subject is that phenol consi«ts 

 of phenyl, with one atom each of H and O. This 

 is very suggeUive, certainly, but we want something 

 more. W. 



WEEDS ON OOFFEK ESTATES IN OLDEN 

 TIMES. 



Sib, — My experience of the period referred to by 

 your correspondent "W. L." does not quite agree 

 with his. Not one of the planters I knew in those 

 days advocated or willingly tolerated weeds. All alike 

 regarded them as most mischievous, especially for the 

 loss of soil occasioned by their _ removal. The idea of 

 their preventing wash is, I believe, quite a modern 

 notion, originating in the minds of men who have 

 forgotten, or who never knew that weeding in 

 the days of old was done with the mamoty, and with 

 a loss of soil immeasurably exceeding any saving ef- 

 fected by the turf of weeds whilst growing. One of 

 my first lessons in weeding was derived from a dis- 

 cussion between two planters on the best mode of 

 using the mamoty. One, A., advocated a deep cut 

 to get up the roots, and open the soil. The other, 

 B., insisted that the thinnest possible slice should be 

 cut off the surface. Both aimed at the same object, 

 to prevent the loss of soil. A. had, of course, to shake 

 oft' the soil from his weeds by hand. B. saved that 

 expense, and loosened less soil ; but A. showed that 

 all the soil so loosened was lost, as tlie ground, when 

 cut in B.'s fashion, was almost impervious to rain; 

 whereas he contended that his deeper cutting opened 

 the soil and allowed more of the rain to soak in, so 

 saving much of the wash. The effect of the discussion 

 in my raiud was a resolute determination to abolish 

 the mamoty altogether, a task which proved one of 

 the stiffest I ever undertook. The scraper, however, 

 gradually superseded the mamoty, and in many cases 

 hand-weeding was adopted, even before clean weeding 

 became general. Though the discontinuance of the 

 mamoty saved a great deal of the waste of soil, weeds 

 continued to be deprecated for the loss of soil they 

 still entailed, as well as for the amount of nourish- 

 ment of which they deprived the coffee trees whilst 

 growing. 



A planter of the present day may naturally ask 

 why, if weeds were such a scourge, we did not get 

 rid of them as we now do? And thereby hangs a tale. 

 To clean a weedy estate involves considerable expense, 

 and can only be done by numerous weedings, following 

 each other in rapid succession, and requiring a steady 

 and continuous supply of labour. The expense was a 

 very serious obstacle to such an operation, iu times 



