403 
Extracts from British and Foreign Journals. 
ON THE GENERATION OF POISONS IN THE ORGANISM 
PRODUCTIVE OF DISEASE. 
A series of interesting lectures, by M. Claude Bernard, 
is being published in the Medical Times and Gazette , “ On 
Experimental Pathology and Operative Physiology . 55 
From a recent one we extract the following observations, 
as appertaining to our domain of science. 
It appears from experiments instituted by Claude Bernard 
that animals debilitated by want of proper nourishment sub¬ 
mit less readily to the agency of certain poisons than others 
in a vigorous state of health. But while this is the case, 
arising from the rapidly increasing debility of the nervous 
system, they, on the other hand, become obnoxious to the 
action of morbid influences of a totally different character. 
He says it has been found that similar affections always have 
a strong tendency to arise in animals in a low state of health. 
Thus the itch (mange) a disease which frequently prevails 
among horses and sheep, is scarcely ever found to attack 
animals in good condition; as in man, the lower classes are 
known to be a prey to vermin, especially in childhood and 
old age. 
The decrease of nervous power equally constitutes a pre¬ 
disposition to putrid, contagious and virulent affections; a 
fact well known to veterinary surgeons. That the chemical 
composition of the blood should incessantly be modified, is 
one of the essential conditions of life; repairing, as it does, 
the daily losses of the economy, and renewing the elements 
of all the tissues which enter into the system; and the 
stronger are the animal’s vital powers, the more rapid are 
the successive changes of the blood. The uninterrupted 
continuance of the circulation is, therefore, in such animals 
of greater importance than in many others, since it cannot 
stagnate without promptly acquiring septic properties. As 
the nervous system presides over all the phenomena of life 
in which motion is concerned, as soon therefore as the nerves 
are impaired, circulation languishes, and the chemical com¬ 
position of the blood becomes thereby liable to important 
changes. If, therefore, it be our purpose to preserve an 
animal from the action of woorara, or similar poisons, we 
must lower its forces; but if, on the contrary, we wish to 
