348 TlMEHRl. 
or bone superphosphate is respectively purchased, whilst as 
insoluble bone phosphate it costs about 5 id., and as mine- 
ral phosphate only 2^d Probably quite half the money 
spent by the colony on manures goes in the purchase of 
phosphorus, it will therefore be seen what a large saving 
would be effected if insoluble could be successfully 
substituted for soluble phosphate. 
