456 
SOCIETY MEETINGS. 
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out, such as strychnia. Its poisonous effects are made manifest 
especially in phenomena pertaining to the nervous system. The 
exact manner in which it produces exitability of the nervous cen¬ 
ters is impossible, at the present time, to explain. We know that 
urea in the presence of water is readily convertible into ammon- 
ium-cai bonate. .Especially is this apt to occur in the presence of 
mucus, which seems to possess a catylitic action—and it has been 
suggested that its toxic properties are made manifest subsequent 
to this conversion. 
That urea is the direct cause of the morbid phenomena, there 
can be little doubt. The history in every case points to this. 
The ownei will tell us that the animal has not performed his 
usual amount of labor for several days previous to the attack, 
during which time he has received the usual allowance of food, 
which probably consisted of oats, which contain a large percent¬ 
age of nitiogenized matter. Examination of the urine again 
stiengthens the theory advanced. It is in every instance loaded 
with the products of tissue waste. Not only is the urine loaded 
with urea, but the presence of ammonia in considerable quantity 
is evident, and the existence of ammonia in the blood is readily 
demonstrable in bad cases. 
I he presence of excessive quantities of urea in the blood causes 
functional disturbance of the nervous system—violently stimulat¬ 
ing the motor tractof the spinalcord, thus producing tonic contrac¬ 
tion of muscles, followed by coma, convulsions and death. The lum¬ 
bar portion of the cord is primarily most affected, and muscles sup¬ 
plied by nerves radiating from the sacro-lumbar plexus arc thrown 
into a state of violent spasmodic contraction. Paralysis does not 
exist during the early and acute stage. Excessive contraction of 
muscles renders the standing position difficult, but sensation is 
unimpaired, and considerable motion is possible. Coma is apt to 
precede a fatal termination, although death is often produced by 
asphyxia. 
The therapeutical indications, clearly, are to eliminate from 
the system the exciting cause of the disease by promoting the 
excietion of the urea. With this object in view, hydragogue 
cathartics are usually administered at the earliest moment pebble. 
As plethoric animals are invariably the victims, the abstraction of 
