104 DRAININGS. 



That a pound's weight of urine is, generally speak- 

 ing, of higher value, as a rtieans of manure, than the 

 same quantity of solid excrjement, follows very plain- 

 ly from what has been said in the preceding chapter 

 respecting its composition. Drainings acquire their 

 great manuring value principally through the large 

 amount of nitrogen and potash they contain. If the 

 drainings were collected which a cow furnishes in a 

 twelvemonth, and dried, about 6 cwt. of solid ex- 

 tract might be obtained from them, which in fertiliz- 

 ing power must be estimated as equal to Peruyian 

 guano, now bought by the farmer in Saxony at from 

 145. 6(i. to <£1 05. Zd. per cwt. In this extract there 

 is contained as much nitrogen alone as in 5 cwt. of 

 the best guano, and so large a quantity of potash 

 that by combustion more than IJ cwt. of potash, 

 worth in commerce X4 IO5., may be readily pro- 

 cured. 



With these statements the agricultural experience 

 of those countries where the true value of drainings 

 as a manure has been longest known, and where 

 they have accordingly been collected and employed 

 with the greatest care, most entirely coincides. Thus 

 in Flemish agriculture the yearly urine of a cow is 

 taxed at three guineas, and this sum is actually paid 

 for it there. And a celebrated English farmer re- 

 lates, that, in manuring meadow-land, he has ob- 

 tained a far greater effect from 160 cwt. of sewer- 

 water from the city of Edinburgh (consisting for 

 the most part of urine), than from 300 cwt. of stable- 



