"194 MANURING COFFEE. 
bound; however, to add, that the French writer makes 
light of the popular argument in favour of cattle manure 
as improving the mechanical condition of the soil. He 
contendz that much larger crops and more profitable 
‘are obtained by means of artificial manures, the 
‘mechanical condition of the soil being improved other- 
wise—by careful culture of course. By the carbonaceous 
matter contained in cattle manure, M. Ville would, and 
probably with justice, set little store, seeing that plants — 
derive the large proportion of carbon of which they 
- are composed (nearly 48 per cent in the case of wheat) 
from the atmosphere. Indeed, when we add together 
‘the constituents which plants derive from air and water, 
_ the remaining balance is very slight as a percentage. 
But’ even fractions of certain substances hosphoric 
? — 
-acid, for example, are of enormous importance. We 
can feel as we read this book that it is not so much 
“ nitrogen and potash as phosphoric acid, lime and culture 
which young coffee estates need, as Mr. Hughes pointed 
out. In the case of old estates, or young ones after 
‘they have borne several heavy crops, however, the 
dominant principle in the crop removed must certainly 
be supplied. If we are to judge by the ashes of the 
z 
- coffee beans, the dominant element (50 to even 55 per 
cent) is potash. Now let us see what are the combina- 
tions which M. Ville advises to be used in the case 
of plants, the dominant principle of which is potash. 
For potatoes and flax his normal manure is composed of 
lb. per acre. 
Calcic superphosphate... ..._ 352 
Potassic nitrate ani oe! 
Calcic sulphate SRN tule 
880 
That for vines and fruit trees would, no doubt, be 
more suitable for voffee, viz :— 
Calcic superphosphate ... ... 528 
Potassic nitrate arin: | 22) 0) 
Calcic sulphate io) Nike dad oor 
1,320 
This is nearly 11 cwt. per acre of substances which 
{even the gypsum) would be costly on coffee estates: In 
both the above cases the amount of nitrogen contained 
in the potassic nitrate is considered sufficient in addition 
- to what is derived from the air and rain. But for 
vines and fruit trees there is a ‘‘ homologous manure,” 
being of the same composition as the normal manure, 
-only that the potassic nitrate is replaced by a mixture of 
