198 OF MANURE. 



portation constitutes not an unimportant branch of 

 industry. But the manner in which this is done 

 is the most injudicious which could be conceived. 

 In Paris, for example, the excrements are preserved 

 in the houses in open casks, from which they are 

 collected and placed in deep pits at Montfaucon, 

 but are not sold until they have attained a certain 

 degree of dryness by evaporation in the air. But 

 whilst lying in the receptacles appropriated for 

 them in the houses, the greatest part of their urea 

 is converted into carbonate of ammonia; lactate 

 and phosphate of ammonia are also formed, and 

 the vegetable matters contained in them putrefy ; 

 all their sulphates are decomposed, whilst their 

 sulphur forms sulphuretted hydrogen and hydro- 

 sulphate of ammonia. The mass when dried by 

 exposure to the air has lost more than half of the 

 nitrogen which the excrements originally contained; 

 for the ammonia escapes into the atmosphere 

 along with the water which evaporates ; and the 

 residue now consists principally of phosphate of 

 lime, with phosphate and lactate of ammonia, and 

 small quantities of urate of magnesia and fatty 

 matter. Nevertheless it is still a very powerful 

 manure, but its value as such would be twice or 

 four times as great, if the excrements before 

 being dried were neutralised with a cheap mineral 

 acid. 



In other manufactories of manure, the excre- 

 ments whilst still soft are mixed with the ashes of 



