COMPOUNDS OF ORGANIZATION. 69 
change from the atmosphere, except a slight deliquescence 
in very damp weather. Ina strong heat it melts, and is 
partly decomposed, and partly sublimed without change. 
It is very soluble in water and alcohol. The fixed alkalies 
and alkaline earths decompose it; it unites with most of the 
metallic oxides, and forms crystalline compounds with the 
nitric and oxalic acids. 
Urea is readily decomposed by boiling its solution in 
water, and supplying new water as it evaporates. Carbo- 
nate of ammonia is disengaged,—acetic acid is formed, and 
some charcoal precipitated. It is considered as containing 
a greater quantity of azote than any of the animal princi- 
ples already enumerated, Its ingredients have been vari- 
ously estimated, owing to the impurity of the urea, and the 
imperfection of the art of analysing animal principles. Dr 
Provr and M. Beragp give its contents as follows: 
Carbon. | Oxygen.| Hydrogen.} Azote. Total. 
Bepinks 19.99 | 26.66 | 6.66 | 46.66! 99.97. 
Berard, | 19.40 | 26-49 | 10.80 | 43.401 100.00 








Urea exists in the urine cf the mammalia, when in a state 
of health. In the human subject, it is less abundant after 
a meal, and nearly disappears in the disease called Diabetes, 
and in affections of the liver. 
7. Sugar.—This well known substance exists in consi- 
derable abundance in milk, and in the urine of persons 
labouring under Diabetes. In the latter fluid, it is to be 
considered as a morbid secretion of the kidneys, occupy- 
‘ing the natural situation of the urea. In milk, however, 
it exists as a constituent principle, and may readily be ob- 
tained by the following process: Evaporate fresh whey to 
the consistence of honey, dissolve it in water, clarify with 
the whites of eggs, and again evaporate to the consts- 
