O?! the Theory of Manures, 



Farm-yard manure, the average of several analyses 



Water 



{soluble in water - - _ _ 



— in potass - - . _ 

 driven off afterwards by heat 

 Salts of potass "j 

 of soda I 

 of lime I 

 of silica J 

 Earthy phosphates -----__ 



45.535 

 10-75 

 14-25 

 18-565 



7-9 



3-0 



100-0 



In comparing them together, he finds 





Bone Dust. 



Farm-yard Manure. 



Water 



Total organic matter - - - - _ 



Soluble matter ------ 



Easily dissolved matter by caustic potass 

 Earthy phosphates _ _ - - - 

 Saline matter ------ 



Azote or nitrogen - - - - . 



11-5 

 33-5 

 10-2 

 41-5 

 55-0 

 55-0 

 1-77 



45-535 

 33-565 

 10-75 

 14-25 

 30 

 10-9 

 •45 



the phosphates in the analysis of bones having been partly con- 

 tained in the easily dissolved matter. 



He next compares them as to the quantities of the respective 

 matters found in each, showing that the total organic matter 

 and soluble matter are nearly alike: but that, as compared 

 with farm-yard manure, there is contained in bones, of 



Easily dissolved matter 

 Earthy phosphates 

 Saline matter 

 Azote - - - 



- 2'9 times the quantity. 



- 18-3 



- 5- 



- 3-9 



30-1 



Thus chemical analysis shows, he says, that 1 ton of bone dust 

 is equal to 30 tons of farm-yard manure. The same mode of 

 analysis is also pursued with rape dust, 1 ton of which is made 

 equal to 18^ tons of farm-yard manure ; and, as this nearly 

 agrees with what is generally considered the ratio in practice, 

 he considers that practice thus confirms scientific results. 



In the above analysis, however, the phosphates are made to 

 perform a double part, being compared, as to their action, both 

 as phosphates and saline matter. The soluble matter in farm- 

 yard manure, also, should have been 43-565. If these had been 

 properly attended to, the result would have been much less ; 

 probably nearer the true amoimt as regards practice, which he 



B 3 



