290 
ON AI.TERATIONS OF THE BLOOD. 
designated in veterinary medicine under the names of aqueous ca¬ 
chexy, the rot, &c. is a disease very frequent and mortal among oxen 
and sheep. This affection, which is rarely sporadic, sometimes epi¬ 
zootic, and often enzootic, ordinarily develops itself under the in¬ 
fluence of insufficient food, associated with an increase of moisture. 
Green vegetables that have not acquired their full development, 
and especially when they are covered with dew, and also plants 
which grow in a humid soil, too frequently produce this disease. 
It is particularly observed in rainy seasons, and in low and marshy 
countries. It reigns in England almost the year through; and in 
our country, and especially in Sologme, it destroys annually an 
immense number of sheep. 
There exists a considerable analogy between anhemia and hy- 
drohemia; the same symptoms mark their commencement, the 
blood presents in both the same character, and both of them 
promptly disappear, if the causes which produce them are removed. 
If the causes, however, continue to exert their baneful influence, 
the disease makes the most rapid progress. The mucous mem¬ 
branes become discoloured—the conjunctiva and the lips, and the 
frsenum of the tongue, are infiltrated—the animals are eager to 
drink—the pulse is small and feeble, while the beatings of the heart 
are strong, and accompanied by a whizzing sound, and which is 
especially recognizable in the carotids. The wool is easily de¬ 
tached, and the tissue beneath the tongue particularly infiltrated, 
if the animal is suffered to remain at pasture. 
If the blood is examined at this period, it is found to be light- 
coloured, and to resemble the water in which flesh has been washed. 
Its coagulation is very slow, and the clot is small, and possessed of 
little consistence. It appears in a receiver like a trembling jelly, 
surrounded by a great quantity of serosity, ordinarily clear, but 
sometimes of a citrine colour. When the blood presents this cha¬ 
racter, the disease is incurable. Dropsy speedily develops itself, 
a serous diarrhoea ensues, and the patient soon dies. 
The lesions are not very dissimilar to those described as attend¬ 
ing anhemia, except that there is a more general infiltration of the 
cellular tissue, and particularly of the dependent portions of the 
frame—serous effusions in all the cavities, and a great quantity of 
entozoa, such as the ascarides, the teniae, and especially the flukes 
which obstruct the biliary canals—all the organs are white, mace¬ 
rated, and without any appreciable organic lesions—the heart and 
the large bloodvessels are almost empty; in a word, there is 
scarcely a trace of blood. Numerous and exact experiments have 
proved that, under the influence of this disease, the blood has di¬ 
minished to a third or even a fourth part of its natural quantity. 
At the commencement of this disease, change of pasture and 
