Oct. 9, 1879] 



NATURE 



559 



microscopical, and it requires very close observation even 

 with the microscope to detect it. It is no wonder, there- 

 fore, that planters found it most difficult to decide when 

 and how to apply remedies, and these considerations, 

 together with others incidental to coffee cultivation, 

 rendered a successful treatment, without scientific aid, 

 both difficult and laborious. 



When the results of the first experiments at Wallaha 

 were published, the importance of the subject led the 

 Colonial Government to take up further investigations, 

 and to render special scientific aid to the planters in con- 

 ducting their experiments. Experiments were organised 

 on a large scale, and carried on in various districts 

 throughout the island. 



Meetings were also held, in which the development of 

 the disease, and the results of more extended experiments 

 and observations were given in detail. 



As a result of this combined activity, a series of reports 

 has lately been presented to the Legislative Council of 

 Ceylon, embodying the results of the " Leaf-disease 

 Inquiry ;" these are published in the Sessional papers of 

 this year. The results of the investigations, so far, are 

 briefly summed up as follows : — • 



1. That the coffee-leaf disease is an organised fungoid 

 Growth, present on the estates in some form or other all 

 the year round. 



2. That in December and the early part of the year it 

 is generally present as an external parasite upon the 

 coffee trees, in the form of long filamentous threads which 

 cover every part of the bark and leaves. 



3. That while an external parasite and in the filamentous 

 stage it is possible to destroy it most effectually, and by so 

 doing to save the trees from the attacks of the fungus for 

 at least one year. 



4. That a mixture of sulphur and lime dusted by hand 

 into the tree in the proportions of one of sulphur to two 

 of lime has been found by experiment to be the most 

 effective and suitable remedy which can be applied. 



5. That the cost of the materials, at present prices in 

 Colombo, together with the cost of application, will not 

 exceed at the rate of R 16-50 per acre. 



6. That the application of sulphur and lime in the pro- 

 portions recommended, by releasing the trees from a 

 heavy drain u on their resources and restoring them to 

 their natural condition, will be attended by a much more 

 profitable result than any expenditure upon artificial 

 manures. 



7. That in order to assist the means used for checking 

 the leaf disease it is most important that planters unite in 

 the application of remedies and that they remove at once 

 all sickly trees on their estates and those not likely to be 

 crop producers, and prevent by every means in their 

 power the re-infection of good coffee. 



8. That in order to secure perfect freedom from leaf- 

 disease it will no doubt be necessary to uproot all coffee 

 trees on abandoned estates and old native gardens, and 

 to take steps to prevent the disease from finding an asylum 

 upon any plants not under careful cultivation.^ 



Judging by these results, which have been obtained by 

 the united action of practical men of considerable know- 

 ledge and experience in coffee cultivation, aided by 

 careful scientific observation, there is little doubt that the 

 leaf disease can now be very effectually and conveniently 

 treated, and if not completely exterminated, at least so 

 materially reduced that it will not seriously injure the 

 crops. 



In the reports just quoted, great prominence is given to 

 the necessity which exists for removing all old and sickly 

 trees and up-rooting coffee plants growing without care 

 or cultivation on abandoned estates and native gardens. 

 Such trees appear to be the worst sufferers from leaf 

 disease, and while they remain, are a continual source of 

 danger to well-cultivated estates One severely diseased 



* Morris's Reports on " Coffec.Lcaf Disease," Sessional Papers, I.egis- 

 •at've CoiincI of Ceylon, 1879. 



tree is said to be sufficient to infect all trees in its imme- 

 diate neighbourhood, and on that account a strong 

 conviction is expressed in the Reports that little good can 

 be expected from remedial measures of any kind, unless 

 great care is taken to prevent the disease finding an 

 asylum on "shuck'' and abandoned coffee. The earnest- 

 ness and intelligence which have characterised the action 

 of the planters during the recent experiments lead to the 

 hope that every means will be taken to check the develop- 

 ment of the disease, and to increase the action of suit- 

 able remedies. The Reports also recommend the extended 

 cultivation of other plants, such as tea and cinchona, in 

 order to break the continuity of the coffee estates and 

 restrict the action of the disease as much as possible. 



On thus reviewing the present condition of coffee 

 cultivation in Ceylon, there is much that is hopeful and 

 satisfactory. Dr. Thwaites in his Report dated March, 

 1 877, remarks that " Notwithstanding the continued preva- 

 lence oi Hemileia vastatrix upon the coffee plants through- 

 out the island, there would appear to be little, if any, 

 diminution in the anxiety to invest in the cultivation of 

 coffee ; the high prices obtained, and the beneficial effects 

 of judicious manuring, are giving so much confidence to 

 planters." This feeling appears still to be maintained, 

 for keen competition and high prices characterise all 

 recent sales of suitable forest land. And while this shows 

 that coffee cultivation still possesses the confidence of 

 investors in new districts, many estates even in the oldest 

 districts, are sold at prices which show they possess great 

 vitality, and that where careful and intelligent cultivation 

 is pursued they still offer a promising and attractive in- 

 vestment. It is gratifying to find that the planters are 

 now quite conscious of the true nature of the disease, and 

 thoroughly aroused to the necessity which exists for 

 treating it on the lines which have proved so eminently 

 successful for the last twenty years 'with the fungoid 

 pests of the hop and vine. 



By the extended cultivation of cinchona, tea, and other 

 products, some of the conditions which have induced, or, 

 at least, encouraged the ravages of the leaf-disease, will 

 doubtless be removed, and in the renewed care and 

 intelligence which are becoming daily more apparent in 

 the methods of cultivation and the npplication of suitable 

 manures, there is every reason to believe that coffee culti- 

 vation in Ceylon will be carried on under much more 

 advantageous circumstances than at present, and while 

 much that is novv under coffee will probably be planted 

 with tea and cinchona, the remaining lands will receive 

 that due care and attention which cannot fail in time to 

 restore the coffee estates of Ceylon to the position they 

 have long held as one of the most successful and important 

 of the enterprises of the East. D. MoRRIS 



Kew, September 3 



OUR ASTRONOMICAL COLUMN 



The Satellites of Mars. — In the Introduction to 

 his Tables of the satellites of Uranus, Prof. Newcomb 

 points out the advantage that might be derived, in syste- 

 matic observations of the satellites by the preparation of 

 a table showing the angles of position and distances 

 corresponding to every 10° in u or the longitude of the 

 satellite in its orbit, counted from the point in which it 

 crosses the plane parallel to the earth's equator. From 

 such a table the appro.\imate positions of the satellites 

 would be obtainable at any one opposition, with no further 

 calculation than is required to determine the value of it 

 for the time of observation. The more rapid geocentric 

 motion of the planet Mars docs not of course allow of this 

 principle of computation being applied so as to attain the 

 same degree of approximation as in the case of Uranus, 

 but even with Mars it is likely that such a table, prepared 

 with the values of the various auxiliary quantities for the 

 date of opposition November 12, may facilitate observa- 

 tions, and we accordingly present one below ; — 



