MODE OF APPLYING URINE. 193 



this material. When the latter salt possessed 

 a high price, this manufacture was even carried 

 on by the farmer. For this purpose the liquid ob- 

 tained from dunghills was placed in vessels of iron, 

 and subjected to distillation ; the product of this 

 distillation was converted into muriate of ammonia 

 by the common method. (Demachy.) But it is 

 evident that such a thoughtless proceeding must 

 be wholly relinquished, since the nitrogen of 100 

 Ibs. of sal-ammoniac (which contains 26 parts of 

 nitrogen) is equal to the quantity of nitrogen con- 

 tained in 1200 Ibs. of the grain of wheat, 1480 Ibs. 

 of that of barley, or 2755 Ibs. of hay. (Bous- 

 singault.) 



The carbonate of ammonia formed by the putre - 

 faction of urine, can be fixed or deprived of its 

 volatility in many ways. 



If a field be strewed with gypsum, and then with 

 putrified urine or the drainings of dunghills, all 

 the carbonate of ammonia will be converted into 

 the sulphate which will remain in the soil. 



But there are still simpler means of effecting this 

 purpose ; gypsum, chloride of calcium, sulphuric 

 or muriatic acid, and super-phosphate of lime, are 

 all substances of a very low price, and completely 

 neutralize the urine, converting its ammonia into 

 salts which possess no volatility. 



If a basin filled with concentrated muriatic acid 

 is placed in a common necessary, so that its surface 

 is in free communication with the vapours which rise 



o 



