424 
EDITORIAL OBSERVATIONS. 
well known, produce their action upon the brain and nervous 
system. They cause no local chemical change, and when 
they prove fatal rarely do they leave behind them any re¬ 
markable appearances; a slight inflammatory blush alone 
pervading the mucous lining membrane of the stomach and 
alimentary canal, as is the case with hydrocyanic acid, &c. 
The statements made respecting the effects produced by 
the yew are varied, and the discrepancies great. Sometimes 
comparatively small quantities have sufficed to destroy life ; 
at others, very large ones have been productive of little or 
no inconvenience to the animal. It is well known that 
horses, cattle, deer, and sheep, partaking of the yew leaves, 
become sensibly affected by them, and death very frequently 
is the result; yet the Germans often mix them with the food 
of their cattle, and it is stated that they tend to fatten 
them. It has been conjectured that, through the digestive 
process becoming thus active, induced by the presence of food, 
the poisonous principle is not developed, or if developed, it 
is assimilated. Is it a product , then, and not a true educt ? 
That this is to a certain extent true is proved by the 
inquiries instituted by Viborg, Husard, and others, who gave 
the leaves of the yew, in doses of from eight to twelve ounces, 
to horses when fasting, and they caused death in a few hours 
after, the animals falling down suddenly, and dying without 
manifesting any pain or suffering. Yet the like quantities, 
being mixed with oats and exhibited to other horses, were 
eaten with impunity by them. This was repeated over and 
over again, and the results were always the same. In a 
former part of this number it is stated that the same thing 
obtains with the ergot. 
Some experiments were performed many years since at the 
Royal Veterinary College, the notes of which are before us, 
in which a pound of yew leaves was given to a horse, and 
they caused death in a few hours afterwards. Subsequently, 
the like quantity was administered to three other horses. In 
two of them the pulse became accelerated, but soon returned 
to its healthy standard; the pituitary membrane was blanched, 
and the appetite impaired for a day or two. In the third case, 
