284 TlMEHRI, 
and the key to the problem rests chiefly in the hands of 
the chemist, who alone is able to point out the nature of 
the ingredients concerned. 
M. VlLLE, the principal advocate for the use of arti- 
ficial manures in place of natural ones, classifies cultivated 
plants into three divisions, or those in which nitrogen, 
phosphoric acid, and potash, respectively, should be the 
dominant constituent in the manure applied to them. 
He places sugar-cane in the second class, as chiefly 
requiring phosphoric acid, and gives instances of 
excellent crops resulting from the application of his 
normal cane manure, consisting of calcium super-phos- 
hate, calcium sulphate and potassium nitrate, to almost 
barren soil in one of the French West Indian islands. He 
states that on the soil of an estate in Guadeloupe which 
hardly yielded one ton and a half of cane per acre without 
manure, there were raised twenty-three tons per 
acre by the use of the mixture above mentioned. And 
in another instance 33 tons 18 cwt. were obtained with 
the aid of his chemical manure from soil that only 
yielded 24 tons 18 cwt. with farmyard manure and 10 
tons 12 cwt. when no manure at all was applied. 
That ammoniacal salts and highly nitrogenous manures 
are of minor importance in cane culture is un- 
questionable. Such manures are valuable for growing 
leaves, seeds and fruits, but not for growing sugar. 
Cane of course requires a certain amount of nitrogen; 
but the ammonia and nitric acid washed out from the 
air by rain should be sufficient to supply a large propor- 
tion of its needs. In fact, M. Ville found in the exper- 
iments at Guadeloupe just referred to above, that by dis- 
