60 



at the rate of 5 to 8 cwt. per acre, according to the mechanical condi- 

 tion of the soil and its more or less effective drainage. 



The mixture of sulphate of ammonia, chloride of potassium, and 

 superphosphate, recommended formerly by my learned friend Dr. 

 Anderson, of Glasgow University, to whom Scotch agriculture and 

 chemical science generally owe so much, besides being very expensive, 

 is too soluble and too acid for the Demerara clays ; neither does it sup- 

 ply any humus or organic matter, in which so many of these soils are 

 very deficient. Nevertheless it is quite equal to the very expensive 

 chemical manure of Professor Ville, which is merely a similar mixture 

 of mineral salts, and certainly not calculated to have much effeet on 

 sugar-cane crops, whatever results it may be said to have upon the 

 highly-cultivated beet- root soils in Europe. In British Guiana such 

 mixtures of nitrates, sulphates, and chlorides are washed out of reach 

 of the cane roots by a single tropical shower, and in dry weather it is 

 not certain that they would be absorbed. 



A better mixture would consist of Peruvian guano, cane ash (or burnt 

 trash), and stable manure or compost heap, to which mixture one quar- 

 ter its weight of gypsum might be added for most Demerara soils. 



Sulphate of ammonia, applied by itself in large quantities, acts as a 

 poison to plants ; in smaller doses its action is that of a powerful stimu- 

 lant, somewhat as sulphate of quinine acts upon a delicate child. I 

 have stated above that its use is to be avoided except in conjunction 

 with relatively large quantities of other manures, or, better, as a power- 

 ful auxiliary to the compost heap 



Hitherto manufactured manures, as is well known, have not been 

 intended as perfect restoratives, and land treated with them alone 

 generally fails in a few years to yield a heavy crop. They are rightly 

 looked upon as auxiliaries in a system of farming — as a kind of supple- 

 ment to a limited supply of farmyard dung. But in the urban cane 

 manure above described we have a perfect restorative — the first of its 

 kind — a manure that will not only cause the soil to yield its utmost 

 when worked with proper care, but will also prevent its ultimate 

 exhaustion. 



Another auxiliary of some importance to the West Indian sugar- 

 grower is lime. Even some of the newer soils would benefit by 

 occasional dressings of lime in the shape of marl or carbonate of lime 

 (not in the burnt or caustic state) ; and this should be followed at an 

 interval of about two months by a liberal supply of manure. 



There are, indeed, three special agricultural difficulties in the direct 

 path of the cane-grower in the West Indies. The first is that he is 

 dealing almost everywhere with a stiff clay soil, diflicult to work even 

 were labour more plentiful than it is ; the second is a remarkable 

 deficiency of lime in many districts; and the third is the very imper- 

 fect nature of the manures hitherto imported, and the implicit faith 

 placed in the restoration of the megass ashes. 



A certain amount of tillage is of course necessary, however perfect 

 the manure applied. Perhaps we shall never possess a manure that 

 will enable us to dispense with labour altogether ; for putting aside the 



