23S 
temperatures. Its volatility is diminished in some degree by 
combination with water, and still more so by combining it 
with carbonic acid, and most when combined with mineral 
acids ; and the ammonia in recently voided urine is, in its 
free and uncombined condition, caustic and noxious to vee^e- 
tation, and likewise so volatile that it will escape into the 
atmosphere as soon as it is produced. Evaporation of this 
valuable substance is then at all times proceeding from the 
stables, yards, and dungheaps, and an immense loss is thus 
sustained. Even as Sprengel states — that one cow in the 
year furnishes at least 15,000 lbs. of urine, and that from 
such quantity no less than 162 lbs. of ammonia could be 
obtained, and which would make 500 lbs. of sal ammoniac, 
the retail value of which in England would be worth £25 
Various expedients have been suggested for the preservation 
of the liquid manures containing ammonia, and to those who 
have written upon the subject, are the following references 
given ; but all are agreed, and the constant practice on the 
Continent is, that before application the urine from cattle 
must be collected in one set of tanks, and the drainings from 
yards in another separate covered receptacle, and that the 
fold yards be made perfectly impervious to water on their 
floors, and the buildings spouted to carry away rain water. 
In the Journal of the Royal Agricultural Society, vol. 1, 
part IV. is a very valuable paper translated from the work 
of Sprengel. 
In the Farmer's Series on Flemish Husbandry, three 
numbers, written by Rev. W. Rham, is an account of the 
manner adopted in Belgium, and of the immense crops and 
produce obtained in that country. 
In Professor Daubeny's lectures is much valuable imforma- 
tion. 
In a paper published by this Society, read by the Rev. W. 
Thorp, at Doncaster, is a comparison of English and Flemish 
