72 TALKS ON MANURES. 



then it is not necessary, I tliink, either to dig a pit or to cover the 

 heap. Those who draw manure from the city in summer, may 

 probably adopt some of Mr. Lawrence's suggestions with ad- 

 vantage. 



The plan of collecting rubbish, brush, old wood, and sods, and 

 converting them into ashes or charcoal, is one which we could 

 often adopt with decided advantage. Our premises would be 

 cleaner, and we should have less fungus to speck and crack our 

 apples and pears, and, in addition, we should have a quantity of 

 ashes or burnt eartli, that is not only a manure itself, but is spe- 

 cially useful to mix with moist superphosphate and other artificial 

 manures, to make them dry enough and bulky enough to be easily 

 and evenly distributed by the drill. Artificial manures, so mixed 

 with these ashes, or dry, charred earth, are less likely to injure the 

 seed than when sown with the seed in the drill-rows, unmixed 

 with some such material. Sifted coal ashes are also very useful 

 for this purpose. 



CHAPTER XVII. 



SOLUBLE PHOSPHATES IN FARMYARD MANURE. 



There is one thing in these experiments of Dr. Voelcker's which 

 deserves special attention, and that is the comparatively large 

 amount of soluble phosphate of lime in the ash of farm-yard ma- 

 nure. I do not think tlie fact is generally known. In estimating 

 tiie value of animal manuies, as compared with artificial manures, it 

 is usually assumed that the phosphates in the former are insoluble, 

 and, therefore, of less value than the soluble phosphates in super- 

 phosphate of lime and other artificial manures. 



Dr. Voelcker found in the ash of fnsh farm-yard manure, phos- 

 phoric acid equal to 13.23 per cent of phosphate of lime, and of 

 this 5.35 was soluble jihosphate of lime. 



In the ash of well-rotted manure, he found phosphoric acid 

 equal to 13.11 per cent of phosphate of lime, and of this, 4.75 was 

 soluble phosphate of lime. 



" That is, indeed, an important fact," said the Doctor, " but I 

 tliought Professor Voelcker clainie:! that ' during the fermentation 

 of dung, the phosphate of lime which it contains is rendered more 

 soluble than in fresh manure.'" 



