766 
THE TROPICAL 
AGRICULTURIST. [March i, 1882. 
liar to Ceylon, and Dr. Thwaites has named ii. a f ter 
Mr. Moon, the first discoverer of it. Another spe-cies, 
Vanilla Walkerias, Wight, almost leafless, and having 
beauliful white flowers, resembling polished silver, 
with stems and fruits resembling those of the vanilla, 
is equally common in the Western Province."] 
LEAF DISEASE AND CARBOLIZED POWDER. 
Colombo, 25th January, 1882. 
Sir, — We notice that reference is made in last 
night's Observer by a Matale planting correspondent 
to the supply of carbolized powder. Be good enough 
to allow us to rectify a wrong impression which ap- 
pears to be current regarding our position in the 
matter. 
We are agents for Messrs. Calvert & Co., and sell 
their various preparations of carbolic acid. Their 
15 per cent carbolic powder is sold by us at B21*50 
per barrel of 200 lb. as frequently advertised in 
your columns. It will be thus seen that the essen- 
tial element weighing 301b. is combined with 170 1b. 
of material on which likewise freight has to be paid 
in addition to import duty. At Mr. Schrottky's sug- 
gestion we undertook to get out the acid (which is 
admitted duty free) and prepare a powder here con- 
taining the same percentage of acid though on a 
somewhat different base. This saving of 85 per 
cent of freight and the whole import duty enables 
us to sell 200 lb. of this locally prepared carbol zfd 
powder, at R12*50, making a very appreciable reduc- 
tion in cost, — a material point in connection with 
the purpose for which the powder was intended. — 
Yours faithfully, LEWIS BROWN & Co. 
COFFEE LEAF-DISEASE :— MR. SCHROTTKY'S 
EXPERIMENTS. 
January 25th, 1882. 
Dear Sir,— The planting community do not seem 
to realize that in my concluding noies, I have spoken 
with excessive moderation of the results of my ex- 
periments: it seems entirely forgotten that I have prac- 
tically proved that leaf-disease can be successfully kept 
in bounds by carbolic acid vapour through all the 
variety of seasons of a whole year in the middle of a 
district where leaf-disease is almost chronically present. 
Let me recall the facts ascertained :— Speaking of the 
bulk of estates, leaf-disease in the Dumbara Valley ia 
more or less prevalent during neaily the whole 
year. The periods of most severe attacks are 
September, October (south-west monsoon), and Decem- 
ber, January (nor' h-east monsoon,) and sometimes also 
during March. This applies specially to Gangapitiya 
estate, which (when I commenced my experiments) I 
was assured was about the wor.-t place for my ex- 
periments, for it Buffered usually even more severely than 
the rest, and certainly when 1 took it in hand it was 
as diseased as it could be. Gangapitiya is the only 
es'ate where the treatment was systematically carried 
out in the early part of the year and the disease had 
practically been got under by the end of May. We 
have spared no expense and trouble at other estates 
(particularly at Pallekelly where though we com- 
menced at the same time, the tr atmeut was sus- 
pended during what we now know the most important 
time of the ye ir) in trying to gain on the fungus at 
a later period, but unsuece?sfully. The fungus later 
on appears togroiv almost quicker than one can kill it. 
Speaking now of last year, the attacks of leaf-disease 
during the 8: W. monsoon in the Dumbara Valley 
were, one can say, less severe than usual, but still 
the disease was prevalent to a large extent. On 
my inspection of the district early in October, I 
found Pallekelly only parily affected ; farther up 
Jhe valley towards Gangapitiya the disease be- 
came worse and in estates immediately adjoining 
Gangapitiya, the disease was prevalent in a bad form. 
It had commenced, I was informed by the rnauagers, 
at the end of June, and had increased steadily, and by 
one of these managers I was informed at the time that 
he did not believe a tree could be found on his estate 
that was free from disease. Gangapitiya was almost 
absolutely free from the disease with the exception 
of a field immediately to the leeward of a native 
estate, which had been neglected for a time, as every 
cooly was wanted to pick crop. When the north- 
east monsoon commenced, the valley began to recover, 
ample rain fell and everything looked luxuriant during 
November. Disease commenced to show again at the 
latter end of that month, ana in beginning of De- 
cember there was not a tree, nay, scarcely a leuf to 
be fnund in the estates immediately surrounding Ganga- 
pitiya, that was not diseased. At Gangapitiya it had 
been a case of a eontinufd, unabated right : a hundred 
times the fungus tried to establish itself, a hundred times 
it was prevented. The manager, in my absence in India 
during the S.W. monsoon, wrote to JVJe-srs. Whittall & 
Co., "Leaf disease continues to crop up in places here 
and there, and I apply the powder immediati-ly wherever 
1 detect it." The disease was most severe during the 
middle of December, and up to the beginning of 
January, Gangapitiya remained unaffected. This closes 
the whole year, for our experiments in the Dumbara 
Valley were commenced in the beginning of January 
1881, and it has been proved by the results at 
Pallekelly Estate that the fungus has no chance 
against the carbolic acid vapour at this time of 
the year. For want of material we had to 
abandon the struggle at Gangapitiya end of Decem- 
ber, and the fungus is evidently endeavouring to 
obiain a footing now; we cannot prevent it; but 
the experiment are complete, the 12 mouths are 
over. A not unnatural qualification of the success 
of these results has been the statement that two 
estates at the very end of the district, appear now 
to be almo^ equally free from leaf disease. I 
have of course given full aitention to this. I find 
that these estates are exceptionally situated, and that 
their past history essentially differs from that of the 
bulk of estates in the Dumbara Valley and from that 
of Gangapitiya estate more panicularly. 
EUGENE C. e-CHROTTEY. 
GARDEN PES IS. 
Kahagalla, Haputale, Jan. 25th. 
Dear Sir, — Can you or any of your readers tell 
me how to get rid of the small black slugs? There 
are so many of them in my gardtn that nothing can 
grow properly. DEW. 
[The following paragraph taken from the Aus'ralasian 
today would seem to meet the case of our correspondent. 
-Ed] 
The Konigsherger Land und Forstivh-thsltoftl iche Zeitung 
contains a short and interesting account of an experiment 
in killing insects and mildew in plants with a solution of 
carbolic acid. One part of carboiic acid was mixed with 
20 parts of water, and left standing 24 hours, after which 
it was well shaken. A coating of oil and fat formed on the 
surface, which was carefully removed, so that nothing but 
water was left. The mixture was poured over a bed of 
radishes and cucumbers, which were badly mildewed, but 
the plants were destroyed by the first and second experi- 
ment. But the quantity of water was afterwards increased 
to 100 parts, and the mixture was successfully used for the 
smallest and most delicate plants. It was poured over 
trees, rose-bushes, and peach trees, and was most effica- 
cious in destroying all kinds of insects. A small quantity 
was also poured over an ant-hill, and the insects forsook their . 
nests with such rapidity that they left their eggs behind 
— a circumstance almost unknown in the annals of ant 
history. A small cherry-tree, the ripening fruit, of which 
