ON THE IDENTITY OF RED-WATER AND SERUM. 193 
soda, potash, or ammonia; then to place the fluid in a water 
bath, and boil it some time, and afterwards to let it cool, and 
add again the acid. The albumen is thus readily precipitated ; 
but if we still continue to boil the water in which the phial 
containing the fluid is placed, we shall this way also obtain a 
coagulum, but not with the same intensity as with the nitric 
acid, as before directed. The various modifications in the colour 
of red-water are dependent on the absence or presence in quantity 
of colouring matter being derived from the red globules of the 
blood, the oxide of iron, which is held in solution chemically 
by the serum. 
Experiment the fifth and sixth shew, that if the coagulable 
portion of the blood passed off by the kidneys, it would quickly 
decompose. Red-water, as the fifth experiment proves, does not 
become turbid or part with its character after two months’ ex- 
posure to solar light ; whilst the cruor of the blood mixed with 
cow’s urine soon underwent the process of putrefaction and de- 
composition. 
In the red-water that occurs under common causes, I have 
rarely seen any fibrine deposited ; and if such were deposited, it 
could not be albumen, as that requires 160 degrees of heat, 
which can never take place in the animal body. If the urine was 
fibrinous in the same ratio in which it is serous, we should have 
a spontaneous coagulable deposit, several cases of which I have 
witnessed in the human subject, and, as in the sixth experiment, 
decomposition would soon ensue in the presence of light. 
In the red- water arising from mechanical injury, where the 
vessels of the kidneys are ruptured, coagulable lymph is found, 
either deposited in the urine, or frequently hanging in shreds from 
the vagina. 
These experiments I have made in order to shew a correspond- 
ing result by the application of the usual tests to prove the 
existence of albumen, whether applied to the urine of red water 
idiopathically produced, or to that artificially made by adding 
serum to cows’ urine. If an excess of acid is added in any of 
the experiments from the first to the fourth, and the fluid is well 
agitated, the curdy deposit is transformed into a pulverulent 
matter, losing its albuminous tenacity. 
In my next communication I intend to test the alvine dis- 
charge. My opinion is, that the acute diarrhoea which fre- 
quently attends this disorder in the primary stage is chiefly 
serum, mixed with a little crassamentum and feecal matter. 
[To be continued.] 
