MANURE. 223 



each at the appropriate time. His formulae are as 

 follows. 



Six pounds bone dust; three pounds leather clip- 

 pings and other animal refuse ; (blood, horns, hoofs, 

 etc.) and one pound gypsum, making in all ten pounds 

 to be added to each square yard of border. This is 

 done in the spring before the buds have pushed. 



As soon as the young shoots are well advanced, he 

 manures each square yard with eight pounds silicate 

 of potassa, and two pounds of the double phosphate of 

 potassa and lime. Silicate of potassa he procures by 

 fusing fifteen parts of quartz sand with ten of potassa 

 and two of charcoal. 



The double phosphate of potassa and lime is pre- 

 pared, by adding 18 Ibs. of sulphuric acid to 24 Ibs. 

 of calcined and pulverized bones. This, after being 

 well stirred, is diluted with water, allowed to stand 

 for three days, treated with hot water and filtered. 

 Carbonate of potassa is then added, until the liquid 

 is slightly alkaline, and it is then evaporated in a cast 

 iron vessel, roasted at a red heat, mixed with the sili- 

 cate, and the whole reduced to powder. 



A vine manured by Persoz with 0.5 kilogr. of sili- 

 cate of potassa, 1.5 of phosphate of lime and potassa, 

 and an equal weight of dried blood and goose dung, 

 put forth in one year a shoot 11 metres in length, and 

 yielded on nine shoots twenty-five bunches of grapes, 



