POTASH. 61 
However these or other discoveries may indicate its mode 
of action, the effect is no less striking and peculiar. 
Gypsum is best applied to the cane, sown in the row, 
before the seed, or afterward used as a top-dressing. As 
an agent in fixing ammonia, chloride of lime is probably 
more effective, being more soluble. 
The effect of gypsum will no doubt be most marked on 
early planted cane, a larger quantity being dissolved by 
the rains. On cane late planted, and preceding a drought, 
it would exert little benefit. 
Polash is observed to be a preponderating ingredient 
in the ash of all sugar-bearing plants. It is, therefore, 
probably not only beneficial directly applied to the plant 
in the form of wood ashes, etc., but the sulphate of lime, 
as above mentioned, seems to effect the conversion of 
salts of potash existing in the soil in an insoluble form, 
into one in which they directly afford nutriment to the 
plant. 
