Farmyard Manure. 233 



The farmei" will, therefore, always be compelled to submit a 

 portion of home-made dung to fermentation, and will find satis- 

 faction in knowing that this process, Avhen well regulated, is not 

 attended with any serious depreciation of the value of the manure. 

 In the foregoing analyses he will find the direct proof that, as 

 long as heavy showers of rain are excluded from manure heaps, 

 or the manure is kept in waterproof pits, the most valuable fer- 

 tilising matters are preserved. But let us now see how matters 

 stand when manure heaps, the component parts of which have 

 become much more soluble than they were originally, are exposed 

 to heavy showers of rain. 



In the first experimental period little rain fell, and this never 

 in large quantities at a time, whilst in the interval of April and 

 August rain was more abundant, and fell several times in con- 

 tinuous heavy showers. In consequence of this the soluble 

 matters in the heap have been washed out, and with them a con- 

 siderable portion of available nitrogen, and the more valuable 

 mineral constituents of dung have been wasted. 



The above analytical data, if I am not mistaken, afford like- 

 wise a proof that even in active fermentation of dung little 

 nitrogen escapes in the form of volatile ammonia, but that this 

 most valuable of all fertilising materials, along with others of 

 much agricultural importance, is washed out in considerable 

 quantities by the rain which falls on the heaps and is wasted 

 chiefly in the drainings of the dungheaps. 



A single fact, it has been truly said, is worth more than a dozen 

 vague speculations. We hear frequently people talk of the loss 

 in ammonia which farmyard manure v;ndergoes on keeping, and 

 this loss is referred by them to the volatilization of the ammonia 

 which is produced in the putrefaction of the nitrogenized con- 

 stituents of dung. I have, however, already mentioned that 

 simultaneously with the ammonia, ulmic, Immic, and other 

 organic acids are generated from the non-nitrogenized consti- 

 tuents of manure, and that these acids possess the power of 

 fixing the ammonia in an excellent manner. If this were not 

 the case it would be difficult, if not im]K)ssible, to exj)lain the 

 circumstance that the proportion of solul)le nitrogenized matters 

 increased consideral)ly in the manure on keeping for a ])eriod of 

 six months, and that during this period the total amount of 

 nitrogen scarcely sufTered any diminution. In April the 

 amount of nitrogen in the soluble matters of the entire heap 

 is ()07"lbs., and by the 23rd of August it is reduced to 

 3'7G lbs. Why, it may be asked, is it not likely that most 

 of this nitrogen has passed into the air in tlie form of volatile 

 ammoniacal compounds? In reply to this question I would 

 answer that a loss taking plaie in this way would be felt 



