26? 
animals more rapidly than that of graminivorous 
animals. In proportion as there is more gelatine 
and albumen in urine, so in proportion does it 
putrefy more quickly. 
The species of urine that contain most albumen, 
gelatine, and urea, are the best as manures ; and all 
urine contains the essential elements of vegetables 
in a state of solution. 
During the putrefaction of urine the greatest 
part of the soluble animal matter that it contains is 
destroyed ; it should consequently be used as fresh 
as possible ; but if not mixed with solid matter, it 
should be diluted with water, as when pure it con- 
tains too large a quantity of animal matter to form 
a proper fluid nourishment for absorption by the 
roots of plants. 
Putrid urine abounds in ammoniacal salts \ and 
though less active than fresh urine, is a very power- 
ful manure. 
According to a recent analysis published by 
Berzelius, 1000 parts of urine are composed of 
Water - 933 
Urea - 30.1 
Uric acid - - 1 
Muriate of ammonia, free lactic acid, 1 
lactate of ammonia and animal > 17*14 
matter - - - J 
The remainder, different salts, phosphates, sul- 
phates, and muriates. 
Amongst excrementitious solid substances used 
as manures, one of the most powerful is the dung 
of birds that feed on animal food , particularly the 
dung of sea birds. The guano , which is used to 
