238 
ON ALTKRA'riONS OF THE BLOOD. 
and then Uie blood, rich in albumino-fibrinous principles, and give 
to these fluids, and particularly to the blood, abnorncial qualities. 
In fact, if we bleed from the jugular animals that have been accus¬ 
tomed to this kind of food, it will be remarked that the blood runs 
slowly at the commencement of its abstraction, especially if the 
opening into the vein is not very large—that it coagulates very 
promptly, and that the clot of blood is much larger than in its na¬ 
tural state. Chemical analysis also demonstrates that the fibrino- 
albuminous and cruoric principles predominate very considerably 
in the serum. There cannot, therefore, remain any doubt of the ef¬ 
fects of food too stimulating on the blood, and, consequently, on the 
prevailing causes of j)olyhtmie. 
After having described the peculiar symptoms which indicate a 
plethoric constitution in animals, M. Delafond remarks that the apo¬ 
plexies which are the consequence of polyMmie have no constant 
locality, and, consequently, that the symptoms which characterize 
them are various. He then endeavours to ascertain the state of 
the blood in these polyhemic congestions, wherever may be their 
seat. This fluid, which in these circumstances is always black, 
flows slowly. Received in a vessel, it is quickly converted into a 
brown-red clot. After twenty-four or forty-eight hours, it is sur¬ 
rounded by a small quantity of deep yellow serum, and putrefaction 
very slowly appears. 
In the animals which have perished from this kind of apoplexy, 
there is an accumulation of black blood in the tissues which were 
principally affected, as the lungs, the liver, the spleen, &c. At other 
times, the blood naturally flows to the surface of some organs, as 
the intestines, and the urinary passages; and, finally,the vena cava 
and the cavities of the heart ordinarily contain black and coagulated 
blood. 
A restricted diet, food in a fluid form, and bleedings, such as the 
case may appear to require, are the proper means to employ in order 
to prevent the dangerous or fatal consequences of polyhemia. The 
curative treatment of polyhemic congestions consists in copious and 
repeated bleedings, and effected as nearly as possible to the seat of 
disease; but after a little while, and when the blood begins to be ef¬ 
fused through the tissues, venesection is more injurious than ad¬ 
vantageous, and only serves to hasten the death of the patient. 
We perfectly agree with the opinion of M. Delafond as to 
the causes which determine this local or extensive plethora, the 
symptoms which indicate it, the fatal consequences to which it leads, 
and the means of preventing its destructive effects; but we do hot 
believe that it is easy to distinguish these congestions from other 
species of apoplexy. We believe that these different affections 
