48 
Work to be done in the Garden . 
and then being dug in wholesale — that I found 
was done because they made good manure or food 
to feed the next crop with — and in the West Indies 
the plantations of Sugar-canes are sometimes chiefly 
manured by their own leaves and ashes, when the 
hollow canes have been used for burning. I am 
sure you wonder what good ashes can do ! And 
the reason will let you into quite a gardening 
secret. Some plants, you must know, which grow 
with hollow stems, like Bamboos and Corn, and, as 
I said, the Sugar-canes, have in their composition 
more or less of a salt called silica. 
Now where a thing must have something in it, 
it cannot very easily be made without that thing — 
and so it is that for a crop of Sugar-canes some 
silica is wanted. 
You think it is there in the ground ? So, per- 
haps, it was at first ; but one crop has eaten it, 
and another has eaten it, and at last, if things go 
on so, it will all be gone. If, however, the crop 
decays upon the ground, as in a desert island, all 
the silica goes back again to the ground, like it 
may do in ashes, and so the crops go on year after 
year the same. I think you will now perceive 
that the soil you put your plants in ought to be of 
a nature likely to suit those plants, and the more 
