m 
causes it to fall prematurely. The Grenada Liberian Coffee oil 
the other hand as Mr. Whitfield Smith correctly states, is “at- 
tacked by a scale insect.” As a matter of fact two distinct 
kinds have been detected : — (i) The circular scale, Aspidiotui 
arhculatus which is also found on the West Coast of Africa 
(Lagos); (2) the long narrow scale chiefly on the ribs of the leaves 
Ischnaspia filiformis, which is very common in the West Indies 
and is also found in England. 
5 * dhese scale insects, though no doubt nous, are not to 
be compared for a moment as a source of danger to Coffee culti- 
vation to the Coffee-leaf disease. Youareaw hat the progress 
distribution throughout the world 01 liis scourge to 
Coffee cultivation has been watched by Kew wit .ssiduous care. 
Originating about 1869, in Ceylon, it spread to uxe Malayan Ar- 
cmpelago in 1876, to Fiji in 1879* to Mauritius in 1881, to Natal 
in 1884 (Kew Bulletin, 1893, p. 362), and to German East Africa 
in 1894. But as I stated in my letter of December 16, 1896, it is 
not known to exist in the West Africa Colonies. Added to this, 
Liberian Coffee is found to be only moderately affected by it. I 
cannot but think, therefore, that all probability is opposed to 
the coi rectness of Sir Alfred Moloney’s statement that the 
disease existed in Liberia in 1875, as Eastern Africa was not 
affected till nearly ten years later. I should be glad to know on 
what precise evidence Sir Alfred Moloney bases it. If true, it 
seals the fate of Coffee cultivation on the West Coast and seri- 
ously imperils that in the New World. 
6. I enclose a memorandum of the most approved method of 
treatment for dealing with scale insects. 
C. P. LUCAS, Esq., 
Colonial Office, 
I am, &c,, 
W. T. THISELTON DYER. 
Downing Street , S. W. 
Mixture for destroying Scale-Insects. 
Heat milk nearly to boiling point and mix with double the 
quantity of kerosene; stir briskly until a thick creamy liquid is 
obtained. • ^ 
Dilute with ten times the quantity of water. Spray or apply 
with a brush, keeping the mixture constantly stirred. 
Sour milk is as efficient as fresh. 
If milk cannot be obtained, or if the mixture is required in large 
quantity, a strong soap emulsion may be used in its place. 
Note on the Correspondence. 
One may safely say that there is no planter here with any ex- 
perience in Coffee, who has not seen scale on Liberian Coffee es- 
pecially in neglected trees or on poor soil. As a rule, I think ’the 
blight does not do much harm, as the trees speedily get rid of it, 
