96 
JOHN R. HART. 
Modes of detecting in ordinary practice the most important 
alteration of urine may not be misplaced here. A simple 
method, consists of the gravimeter for measuring the specific 
gravity of fluids, a little blue and red litmus paper, a test tube^ 
a spirit lamp, and a vial of nitric acid. 
The urine if acid will redden the blue litmus paper ; if alka-^ 
line, it will turn the red paper blue. If neutral it will produce 
no change in either color. If there is no cloud in the urine a 
small quantity of it may be placed in the test tube over a spirit 
lamp. Should a white deposit be formed it must be either al¬ 
bumen or the earthy phosphates. The addition of a drop of 
nitric acid will coagulate the albumen more firmly, but dissolve 
the salts. If the urine is very high colored it may be supposed 
to contain either coloring matter or bile or blood, or an excess 
of uric acid. If blood be present, heat will cause the liquid to 
lose its transparency, as will also nitric acid ; whereas heat will 
not affect the bile pigment, and nitric acid will at once turn it 
green. If uric acid be the cause of the dark color of the liquid 
examined, the addition of nitric acid will precipitate it in the 
form of a brownish sediment. Urine made green by the addi¬ 
tion of nitric acid, contains the coloring matter of bile. Mucous 
in urine, if much, is generally owing to vesical catarrh or to 
enlargement of the prostate gland. Pus may be derived from 
the inflammation of the pelvis of the kidney, or from the lining 
membrane of any part of the urinary passage, or from abscess of 
the kidney or prostate gland. 
Muscles. —The characteristics of muscles should be taken 
into consideration in this disease. In the first place, in a state 
of rest, living muscle has an alkaline reaction ; in dead muscles 
and in muscles in contraction, the reaction is acid, as well as 
acid potass., phosphate, and carbonic acid. Living muscle is to 
a certain extent translucent, extensible and elastic ; dead muscle 
is opaque, rigid, inextensible, and has lost its elasticity. This 
is due to coagulation of myosin. Why some animals remain 
lame and do not recover their normal condition of muscles in the 
posterior parts is due to a condition of fatigue, due either to in- 
