73° 
THE TROPICAL AGRICULTURIST. [February i, 1882. 
To the Editor of the Ceylon Observer. 
A QUININE FACTORY FOR COLOMBO. 
Dear. Sir, — Mr. P. D. Millie's itlea has been anti- 
cipated, and the setting up of a quinine factory in 
Colombo has been determined on. Orders are in course 
of execution for the machinery, and an experienced man 
is to be imported with it. B. B. 
THE CRYPTOGAMIST AND LEAF-DISEASE. 
Dear Sib, — Like the postscript of a 'lady's letter, 
the last remarks of the ciyptogamist are the most 
interesting of his communications. At best, however, 
it is but painful, disappointing reading ; so little 
hope, so little practical information, so much more that 
we would like to know. 
1. — Mr. Ward still stoutly maintains that there is 
" no evidence of a necessary predisposition to disease 
on the part of the coffee plant," and that "no 
special predisposition on the part of the coffee is re- 
required for its infection." To prove this Mr. Ward 
" proceeded to make experiments by sowing the 
spores of Hemileia on all kinds of coffee leaves, * * 
to see if one kind was more predisposed than another." 
Now I submit that this artificial test was not a fair 
one Planters don't want to know whether if artificial 
means are employed all coffee trees are equally liable 
to take in the fungus, and to suffer from disease, but 
whether they are so or not, when subjected to the 
ordinary operations and conditions of nature. His 
experiments moreover, such as they were, seem to have 
been incomplete for he makes no reference whatever to 
Liberian coffee. When an epidemic breaks out, say 
cholera, it is pretty well known that some men 
naturally seem less liable to take it than others in 
ordinary and similar condition ; but if all were arti- 
ficially inoculated with the virus, it is but reasonable 
to conclude that all would become affected. Mr. 
Ward tries to support his conclusion by the analogy of 
bathing boys attacked by leaches. But unless the leeches 
were as plentiful as the myriads of spores are, there is no 
ground for analogy ; if they were, and the boys by position 
were all equally liable to attack, then if some were 
more bitten than others, I would undoubtedly con- 
clude that their bodies were more susceptible to at- 
tack, more liable to suffer from the leeches. From 
impurities of the skin leeches will often refuse to at- 
tack by themselves, much more to bite. If then there 
be any analogy in Mr. Ward's parallel, it is rather, 
against than for his conclusion. In another part of 
hie remarks Mr. Ward says: " in many eases known 
tu uie it is simply because the coffee lias not yet 
become the prey of the fungus that it looks so well." 
This surely implies a want of predisposition, or if 
not, will Mr. Ward explain ? I make no attempt to 
controvert his theory, but I cannor, see that he has 
proved its truth, while observed facts seem to be against 
it. Every planter knows of fields dotted all over 
with fine vigorous coff e trees apparently free, or 
comparatively free, from the fungus, while the sur- 
rounding trees are covered with the pest. To all 
appearance the natural conditions are similar, same 
foil, elevation, climate, exposure, treatment. I here 
may of course be dissimilar conditions, but if so what 
are they '! Planters would be only too glad to know 
for they evidently are the cause of the exemption. 
2. —Mr. Ward has not made it clear that there is no 
hope to be got from the suggestion that the trees might 
be mado to take up something by their roots into or 
with their sap which would destroy ihu fungus with- 
out seriously injuring the trees. Although he discoun- 
tenances this notion, wo know that trees will take 
up by thoir root iuto their system substances other 1 
than food, and we also know that what may kill 
minute life will often not merely not harm but may 
do good to larger life. If the sap can bathe the 
leaf cells, and the mycelium find its way through 
the passages between the loosely arranged cells, then 
surely there is scope for the weak solution of some 
remedial substance. 
3. — Mr. Ward considers that damp corners, ravines, 
and hollows, are particularly subject to the germina- 
tion of the fungus. My experience, however, 
and I should think that of most planters, 
is just the. opposite. It is the fine ravines and hollows 
that seem to escape, while the exposed ridges and faces 
are often chronic in their suffering. 
4. — Again as a matter of experience I am not 
satisfied that shade is a good thing : it may for a time 
ward off an attack, but when the visitation does eoine 
I have often teen it worse, and remain longer, than on 
adjoining unshaded coffee. This experience seems to 
be theoretically supported by many of Mr. Ward's 
other remarks, as lor instance, when trying to ex- 
plain why the leaves on lower branches are more 
affected than those on the higher branches. 
5. — The many reasons Mr. Ward gives forgathering 
up and destroying the fallen leaves would tell more 
strongly in favor of actually plucking the diseased 
leaves from the trees, but both suggestions must I fear 
be consigned to the limbo of the impracticable. 
6. — Mr. Ward is not very clear, but he seems to 
recommend the postponement of pruning till about 
June on the Kandy side. Evidently Mr. Ward has 
overlooked the fact that even in Ceylon there is a 
special growing season, particularly for our coffee : and 
the general concensus of planting opinion is that early 
pruning say in Jauuary and February is, if one can 
afford the labor and expense, much better for the 
tree, even as regards leaf disease, than a late pruning 
such as he recommends. 
6. — If spores are so vriy numerous, if a generation 
is often so very short, some three weeks, how is it 
that there used to be, a':d still is to a great extent, 
such a periodicity in the attacks of leaf disease ? 
7. — If belts are such a protection how is it, that 
a natural belt of forest some dozen miles in width 
over hills some two thousand feet at least above the 
coffee on either side, is no pi-otection, though only 
from that side is there any source of infection. 
We come now to the Harrow experiment. It was 
regarding this experiment, I some time ago warned 
the planters, that Mr. Ward had very unfairly 
told us all that was good, without giving us the 
slightest hint of anything that was unsatisfactory. 
It would seem that the number and weight of 
foliage on the sulphured and limed coffee was rather 
greater than on the untreated coffee, The treated 
coffee was however at a rather higher elevation, and 
less exposed apparently to the S. W. monsoon. It 
would be difficult also to say to what extent the 
lime alone, acting as a manure, would darken and 
increase the foliage. It is to be regretted that in 
the conducting of such an exact scientific experiment 
no attempt was made to compare the number and 
weight of foliage in the respective fields, preparatory 
to the making of the experiment. Why also were 
leaves of two inches in length and upwards only 
taken. It must in the taking of such a vast num- 
ber of leaves have been very difficult to avoid tak- 
ing leaves a shade under, and having leaves a shade 
over, the arbitrarily fixed two inches. 
However the proof of the pudding is the eating of 
it, and the question must be asked "Did it pay ?'' 
In answer w<- find that to put it iu the strongest 
light, coffee with an extra expenditure of R2U 47 per 
acre on sulphur and lime gave some 15 lb. more an 
acre of produce ready for shipment, worth at the rate 
,of R50 per cwt. the sum of R6.70. The quantity 
