664 Transactions of the American Institute. 



cases become such a serious nuisance, and which, if persevered in, 

 must become a source of absolute danger. 



I believe, also, that this stuff being confined in air-tight pipes, and 

 shut off from the action of the atmosphere, would be subject to very 

 little change by fermentation, during the twenty-four hours that any 

 part of it would remain in the pipes, and, consequently, there would 

 be little or no escape of noxious gases from it. I believe that it would 

 be difficult to accustom ourselves to either of those systems that would 

 require the removal from our houses, at stated periods, vessels con- 

 taining such disagreeable contents. The pneumatic system, however, 

 provides a way that is free from any objections on the score of 

 modesty or decency. This system has been in successful operation in the 

 city of Prague, Bohemia, for about two and one-half years. In Brunn, 

 Moravia, some forty reservoirs have been in operation a little over 

 a year. In the city of Hanau, near Frankfort, it has been in opera- 

 tion about a year; and when I left Germany, last August, work* 

 were being completed for Heidelberg, Manheim and several other 

 places in Germany; beside, works were in a far advanced stage for its 

 introduction in a large part of the city of Amsterdam, Holland. 



By either of those four systems we accomplish one very important 

 object, but one that I fear is not yet sufficiently appreciated. It is 

 this : we are enabled by them to restore to the earth a large amount 

 of the important elements of productiveness, that have been taken 

 from it by the food which we consume. 



It is discouraging to find gentlemen, who are extensively engaged 

 in agriculture, and even those occupying high official positions in our 

 agricultural societies, giving way to the ignorance and prejudices that 

 have grown up against the use of fecal matter as manure. 



Let us compare its component parts with those of two of the most 

 popular organic manures : 



Guano contains uric acid, phosphoric acid, oxalic acid, carbonate 

 of ammonia and a small portion of earthy salts ; the nitrogen of the 

 uric acid and carbonate of ammonia being the principal elements upon 

 which the value of the guano is based. 



The fluid parts of horse manure contains urea, hippuric acid, soda 

 and common salt, or chloride of sodium. "We have here the same 

 important element, nitrogen, contained in the urea and hippuric acid, 

 which constitutes almost the entire value of this fluid. 



In the fluid parts of the human excretion we have in 1,000 parts 

 about fifty parts that are composed to a great extent of organic 

 nitrogen, a, the urea ; b, lactate of ammonia ; c, uric acid ; d, phos- 



