1054 BLOOD, MILK, URINE. 



The following analysis by Berzelius exhibits the composition 

 of urine in its ordinary state, in 1000 parts : 



Water. ..... 933.00 



Urea. . . . . .30.10 



Uric acid. . . . . .1.00 



Free lactic acid, lactate of ammonia, and ani- 

 mal matter not separable from them. . 17-14 

 Mucus of the bladder. . . . 0.32 



Sulphate of potash. . . . 3.71 



Sulphate of soda. . . . 3.16 



Phosphate of soda. . . . 2.94 



Phosphate of ammonia. . . .1.65 



Chloride of sodium. . . . 4.45 



Hydrochlorate of ammonia. . . . 1.50 



Earthy matters, with a trace of fluate of lime. 1.00 

 Siliceous earth. 0.03 



URINARY CONCRETIONS. 



There are several distinct species of urinary calculi. 



1. Xanthic oxide, a very rare calculus, discovered by Dr. 

 Marcet. It has a light brown or bright brown surface ; its frac- 

 ture is scaly, with a brown or deep flesh colour, and becoming 

 resinous by friction. It is distinguished by being entirely 



x soluble in caustic potash, and precipitated by carbonic acid. 

 It is thrown down as a white precipitate, which agglutinates 

 in drying, and forms a pale-yellow, hard mass, which acquires 

 a waxy lustre by friction. It is soluble in alkaline carbo- 

 nates ; also in nitric acid without effervescence. Its composition 

 is expressed by C 5 N 2 H 2 O 2 . 



2. Cystic oxide, a rare calculus, discovered by Dr. Wollas- 

 ton. It appears, when broken, to form a yellowish-white, 

 confused crystalline mass, having a brilliant waxy lustre. It 

 is distinguished by its solubility in caustic potash, from which 

 it is deposited on the addition of acetic acid, in hexagonal 

 plates. It is also soluble in ammonia. The mineral acids 

 dissolve cystic oxide with ease, and form crystalline com- 

 pounds with it. The compound with hydrochloric acid is 



