URINE. 
analysis, and is then, of course, much less valu- 
able as manure, It also contains less manuring 
matter the more water the cows drink,—a cir- 
cumstance to which attention must be paid. In 
summer, it passes very quickly into a state of 
putrefaction, and much ammonia is consequently 
developed in the form of gas; likewise carbonic 
acid, and a portion of sulphuretted and phos- 
phuretted hydrogen, which likewise partly as- 
sume the gaseous state. The last two gases are 
the cause of the intolerable odour of putrefying 
urine. The caustic ammonia arising in every 
case from the decomposition of the urea and the 
other organic bodies of urine which contain ni- 
trogen remains partly dissolved in water, and is 
the substance through which urine not properly 
putrefied is so apt to injure plants. If, on the 
contrary, the urine remains a long time exposed 
to the air, the caustic ammonia absorbs from it 
carbonic acid, becomes mild, and the urine may 
then be employed without danger as a manure 
for vegetation. That the putrefied urine actu- 
ally contains much carbonic acid combined with 
the ammonia, we find by mixing it with mineral 
acids, when strong effervescence ensues, An- 
other analysis by Sprengel of cattle urine 
which had been exposed to the air for a 
month to putrefy, and had lost very little by 
evaporation, exhibited the following as the 
composition of 100,000 parts by weight :— 
95,442 of water, 1,000 of urea, along with a por- 
tion of resinous colouring matter, 0 of albu- 
men, 40 of mucus, 250 of benzoic or hippuric 
acid, 500 of lactic acid, 1 of acetic acid, 165 of 
carbonic acid, 487 of ammonia, occurring partly 
in an uncombined state, 664 of potash, 554 of 
soda, 338 of sulphuric atid, 26 of phosphoric 
acid, 272 of chlorine, 2 of lime, 22 of magnesia, 
1 of sulphuretted hydrogen, 5 of silica, 1 of oxide 
of iron, and 180 of sediment consisting of phos- 
phate and carbonate of lime and magnesia, alu- 
mina, silica, and oxide of iron, and oxide of 
manganese. Thus, if the urine of cattle, which 
has been putrefying for a month, contains more 
than as much again of ammonia as urine in its 
fresh state, it would obviously have contained a 
still greater proportion if some of it had not eva- 
porated during the time; and that this escape 
of the gas actually did take place was made evi- 
dent, not only from the smell, but also on the 
application of chemical tests,—for instance, by 
holding muriatic acid near it, when a dense 
white vapour of sal-ammoniac, in every case, 
immediately ensued. The ammonia, which es- 
capes in the form of gas, naturally occasions a 
direct and not inconsiderable loss of that ele- 
ment to which the putrefying urine owes its 
principal action as a manure; so that it is of 
importance to add to the decomposing urine 
some substance containing an acid principle, 
which not only combines with the ammonia as 
it becomes gradually developed, but also neu- 
tralizes it. See the article Lreurp Manure. 
D49 
When cattle urine is left for three months or 
longer in the tank, a considerable portion of the 
carbonate of ammonia formed in it is lost, for 
the carbonate evaporates as well as the caustic 
ammonia, though more slowly. A small quan- 
tity of carbonate of ammonia is also continually 
evaporating from urine even when mixed with 
water; and therefore when the caustic ammonia 
has been rendered mild by its conversion into 
carbonate, no time should be lost in applying it 
as a manure to growing plants. The escape of 
the volatile ammonia, however, is prevented the 
most completely when the urine is mixed with 
humus, and then either left to putrefy or laid 
on the field and immediately ploughed in. Urine, 
five or six months old, contains not a trace of 
its original urea, mucus, and albumen; on the 
other hand, there are found in it carbonate, sul- 
phate, and humate of ammonia, humates of lime 
and magnesia, common salt, and also some ben- 
zoate, lactate, and acetate of ammonia. The 
lactic, acetic and benzoic or hippuric acids, 
belonging to the class of organic bodies, do not 
injure vegetation, being united to the ammonia, 
and therefore in some measure incorporated as 
inorganic matters.—If urine has not been mixed 
with water, and contains a certain quantity of 
solid excrement, it is said to be a sign that it 
has acquired its proper maturity in the tank 
when no further scum or froth arises to the sur- 
face even when the liquid is stirred up. No 
doubt, this is a certain proof that the fermenta- 
tion of the urine is completed, and that it may 
now be applied without injury to growing vege- 
tables; for the scum, or bubbles, are occasioned 
by the carbonic acid, which cannot even begin 
to escape until it has saturated all the ammonia 
present. Still, although urine which froths no 
longer contains caustic ammonia, and conse- 
quently is no longer injurious to vegetable life— 
how much ammonia up to the moment when 
this is the case has escaped in the form of gas, 
and how much of the choicest manuring element 
has been up to that point lost by the urine! On 
this consideration we should at once hasten to 
convey the urine as fresh as possible to the field, 
but to a field which has no crop on it. In fact, 
whoever is obliged, for want of straw, to collect 
the urine separately,—whoever, if he be com- 
pelled to do this, mixes no water with it, or who 
fails also to employ some neutralizing substance 
to combine with the ammonia which is produced 
in so great a degree during the summer, suffers 
a loss of manure which exceeds all belief! It is 
indeed only a gaseous substance, and not a solid 
material visible to the eye, which thus escapes 
and is lost; but for all that it is of greater im- 
portance to the nourishment of plants than per- 
haps any other portion of the excrements. 
Sheep drink very little water, and therefore 
void comparatively little urine; yet even when 
they take no drink whatever, the water of their 
urine and that found in their solid excrements 
