Cane Soils and Artificial Manures. 285 
pensing with the nitrogen in the manure employed, it 
still sufficed to yield twenty-two tons eight hundred- 
weights of cane to the acre.* 
Even if nitrogenous manures could not be dispensed 
with altogether, it would be a great point gained to 
reduce their use to a minimum. Not only is nitrogen 
paid for at an immensely higher rate than any other 
manurial substance, but the supply of matter containing it 
is limited, and likely to decrease unless new and unex- 
pected sources are discovered. The exhaustion of 
the guano deposits is only a question of time, and should 
coal gas be superseded by the electric light the most 
important source of our ammoniacal salts will depart 
with it. 
According to the analysis of PAYEN, ripe sugar-cane 
(Otaheite) has the following centesimal composition : — 
Water ... ... ... ... ... 71-04 
Sugar ... ... ... ... ... 18-00 
Woody matter ... ... ... ... 9-56 
Albumen and nitrogenous matter f ... ... 0-55 
Wax, fat, resin and colouring matter ... ... 0-37 
Mineral matters or salts ... ... ... 0*48 
100-00 
Of the above substances only the mineral matters and 
perhaps a portion of the nitrogen are supplied by the soil ; 
so, apart from its physical condition, the difference be- 
* He also found by employing no lime in his manure (the other 
ingredients remaining the same) that only twenty tons of cane were 
obtained per acre, while without potash only fourteen tons, and without 
phosphates only six tons, of canes were produced. His instructive 
experiment thus bears out his statement respecting the importance 
of phosphoric acid as a cane fertilizer. 
f Containing about 0-1 per cent, of nitrogen. 
NN 
