192 MANURING COFFEE. 
The principles here exemplified holding good in all 
cases, although of course certain soils are rich in the 
main elements of fertility while others are deficient 
(M. Ville analyses the soil by growing plants in patches 
of it), the use of certain combinations of the four sub- - 
stances last noticed are recommended, by means of 
which a soil can be made to yield profitable crops 
continuously while it positively improves in quality 
instead of being exhausted. For a wheat crop of 33 
bushels per acre, per annum, M. Ville would apply a 
dressing consisting of 
Per acre. Cost, 
Caleic superphosphate ... 176 lb £0 7s 8d 
Potassic chloride at 80° 88 ,, 0 6s 5d 
Ammonia sulphate vi Wie 111s 2d 
Calcic sulphate i Ga, 0 0. 8d 
Total...528 Ib £2 5s lld 
The ‘“calcic sulphate” of this receipt is just gypsum 
or plaster of Paris, and there can be no doubt 
that the above would form. an excellent application 
“to coffee. The cost, however, we fear would have to 
be quadrupled. M. Ville has the strongest possible 
belief, which we share, that chemical science will 
yet discover a mode of extracting from the atmosphere 
all the nitrogen required in agriculture. As it is, cer- 
tain plants, notably the legumes, absorb very large 
quantities, and hence the value of vetches, lupins, &e., 
ploughed green into the soil. We do not know to 
what extent the coffee tree, whicn is popularly re- 
garded as yielding ‘‘ beans,” derives. nitrogen from the 
atmosphere, but M. Ville classes sugar-cane with turnips, 
seeds, Jerusalem artichokes, sorghum and maiz> as 
meeting no nitrogen (ammonia) in the manure applied 
to its culture. The mixture he recommends in this 
case consists of lime in two forms and of potash thus :— 
Per: dere "Cost, 
Calcic superhosphate... 528 lb. £1 3s Od 
Potassic nitrate ak Toye. 118s 4d 
Calcic sulphate des 3o2 3, 0 2s 6d 
Total..-1,056 Ib £3 4s Od 
If we could afford to give our coffee trees about 9 
cwts. per acre of such a mixture as the above, we have 
no doubt the response in the shape of crop would be 
large, but we suppose that in this case also we should 
have to calculate on at least a quadruple cost, say 
£12 per acre? That is the difficulty—the one of cost 
—of the coffee planter in experimenting with a adopt-- 
ing system of manuring, however, strongly recom- 
mended. 
