120 



STALL-MANURE AND STRAW. 



The putrefaction of fresh drainings proceeds, 

 moreover, very rapidly, when, as usually happens, 

 they are placed in contact with such as are already 

 putrid, or when the sediments at the bottom of the 

 reservoir are from time to time stirred up. 



VI. STALL-MANURE AND STRAW. 



1. Alteration of Stall-Manure by Keeping. 



Ordinary stall-manure is a varying mixture of 

 animal excrements, urine, and straw-litter. It is 

 strong, in proportion to the quantity of urinous 

 liquid it has absorbed ; weak, in proportion to the 

 small amount of urine and the large quantities of 

 straw it contains. With this circumstance also its 

 greater or less facility of decomposition entirely co- 

 incides. Amongst these ingredients the urine has 

 the greatest tendency to putrefaction and decay, and 

 straw the least ; manure rich in urine will, therefore, 

 pass more rapidly into fermentation, and arrive more 

 quickly at what is called " ripeness," than when poor 

 in this constituent. 



Fresh manure is, however, no means of nourish- 

 ment to plants ; it becomes so only by what is termed 

 fermentation, that is, by a previous putrefaction and 

 decay. The changes which manure undergoes by 

 these processes of disintegration extend chiefly to its 



