202 MANURING COFFEE. 
“ Tf we cultivate side by side peas and wheat, or 
peas and beet-root, and the peas yield well whilst the 
wheat turns out badly, we are able to conclude unhesit- 
atingly that the land is provided with the mineral but. 
lacks the nitrogenous matter; on the other hand, if the 
wheat succeeds equally well, we may be certain that the 
land contains both the mineral and nitrogenous matter. 
Can you conceive a method which is more practical and 
yet at the same time eimpler and more conclusive ? ” 
We should think that maize would be the best 
substitute for wheat in any similar experiments in 
Ceylon. But we know already that the vast majority 
of our soils are specially deficient in phosphoric acid 
and lime. Tbese, therefore, we can never go wrong 
in adding liberally, seeing to it, of course, that nitrogen 
and potash are present or that they also are supplied. 
More interesting, perhaps, to us as colonists is the ~ 
result of an experiment on the cultivation of sugar- 
canes carried on at Guadeloupe by M. de Jabrun, an 
old settler in that colony :— Tons. Cwt. 
Normal manure hes ie 23 0 
Manure without lime ... au 20 0 
bse 3 potash... mA 14 0 
a a phosphate . ... 6 0 
Hs He nitrogen wee 22 & 
With no manure i 1 4 
M. Ville remarks, ‘‘If I add that the sugar cane 
obtains its nitrogen from the air [why then are 
ammoniacal guanos so largely used in the culture of 
the cane?—EKp.]| you will conclude from these figures 
that the soil is very defective in potash and calcic. 
phosphate.” We should certainly conclude that the 
soil was utterly worn eut. So much the more valuable 
is the manure if obtainable at any reasonable eost. 
The debilitating effects of leaf disease on the coffee 
plants, and the consequent falling off in bearing power, 
have given so much additional interest to the question 
of the best and cheapest forms of fertilizers, that we 
need make no apology for once again referring to 
the work of M. Ville on artificial manures. This 
writer insists that the value of farm-yard manure (dry) 
consists in the nitrogen about 2 per cent, phosphoric 
acid, about 1 per cent, lime from 3 to 5 per cent, 
and potash from 24 to 4 per cent, contained in it. 
Carbon, hydrogen and oxygen, constitute from 60 to 
65 per cent of this material, and silica and sand — 
make up from 17 to 25 per cent more. The other | 
materials are of slight importance. M. Ville’s own 
analysis of stable dung (undried) shewed that 1,000 
parts gave no less than 800 of water, 4°16 nitrogen, 1°76 
phosphoric acid, 4°92 potash and 10°46 lime. Contrast. 
