464 URATE, AND SULPHATED URINE. 



Quantity of urine. Solid matter. Containinor of urea. And yielding of ammonia. 



Man 1000 lbs. 67 lbs. 30 lbs. 17 lbs. 



Horse 1000 " 60 " ? 1 



Cow 13000 " 900 " 400 " 230* " 



How much of all this enriching matter is permitted to run to waste ? 

 The sohd substances contained in urine, if all added to the land, would 

 be more fertilizing than guano, which now sells at XIO a ton. If we 

 estimate the urine of each individual on an average at only 600 lbs., 

 then there arc carried into the common sewers of a city of 15,000 in- 

 habitants, a yearly weight of 600,000 pounds, or 270 tons, of manure, 

 which, at the present price of guano, is worth £2700, — which would no 

 doubt prove more fertilizing than its own weight of guano, and might be 

 expected to raise an increased produce of not less than 1000 qrs. of grain. 



The saving of all this manure would be a great national benefit, 

 though it is not easy to see by what means it could be effectually ac- 

 complished. What is thus carried off by the sewers and conveyed 

 ultimately to the sea, is drawn from and lost by the land, which must, 

 therefore, to a certain extent be impoverished. Can we believe that 

 in the form of fish, of sea tangle, or of spray, the sea ever delivers 

 back a tithe of the enriching matter it daily receives from the land ? 



2°. Urate. — In order to prevent a portion of this waste, the practice 

 has been introduced into some large cities of collecting the urine, add- 

 ing to it one-seventh of its weight of pov/dered gypsum, allowing 

 the whole to stand for some days, pouring off the liquid and drying 

 the powder. Under the name of urate this dry powder has been high- 

 ly extolled, but it can contain only a small portion of what is really 

 valuable in urine. The liquid portion poured off must contain most 

 of the soluble ammoniacal and other salts, and even were the whole 

 evaporated to dryness, the gypsum does not act so rapidly in fixing 

 the ammonia as to prevent a considerable escape of this compound 

 as the fermentation of the urine proceeds. 



3°. Sulphated urine A method of more apparent promise is that 



now practised by the Messrs. Turnbull of Glasgow, of adding diluted 

 sulphuric acid to the urine as the ammonia is formed in it, and subse- 

 quently evaporating the whole to dryness. From the use of tl.is sub- 

 stance very favorable results may be anticipated.! Still none of these 

 preparations will ever equal the urine itself part of the efficacy of 

 which depends upon the perfect state of solution in which all the sub- 

 stances it contains exist, and upon the readiness with which in this 

 state they make their way into the roots of plants. 



4°. Loss ofcouPs urine. — When left to ferment for five or six weeks 



'The numbers given above, and in p. 40^1, are calculated from the analysis oi the urine 

 of tlie horse by Fourcroy and Vauquelin, and ofthatof the cow by SpreJigel. Boussingault, 

 however, obtained very different results. Thus a cow and a horse, on which his experi- 

 ments were made, yielded a quantity of urine which in a year would have amounted to, 

 and would have contaiiieil, in pounds — 



Containins of Capable of yicld- 



Quaniity. Sulid matter (total). Inor^ranic matter. Nitrogen, ing of ammonia. 



Cow 6570 773 " 300 29 35 



Horse HOC 243 m 30 36 



The cow yielded at the same lime 19 lb.«. of milk each day, which accounts f()r the 



smaller proportion of urine voided, than i.^ given in the text. It is remarkablp, however, 



that the quantity of nitrogen contained in an equal weight of the urine of the horse was in 



this case so much greater than that of the cow— and in that the whole amount which would 



have been yielded by that of a cow in a year should be so very much less tlian in the re- 



