TOBACCO. 481 
heat above that of boiling water.. A quantity of 
watery fluid came over, on the surface of which 
was a film of unctuous substance, which he calls 
the empyreumatic oil. Mr. Brodie found that 
two drops of this oil applied to the tongue of a 
young cat with an interval of fifteen minutes 
occasioned death. A single drop suspended in 
an ounce of water and. injected into the rectum 
of a cat, produced death in about five minutes. 
One drop suspended in an ounce and a half of 
mucilage and thrown into the rectum of a dog, 
produced. violent symptoms, and a repetition of © 
the experiment killed -him. | 
Tobacco has been used both as a seniac int 
prophylactic, and as a medicine. In the former 
eases it has not been taken internally, but only 
kept in contact with absorbing surfaces. It is 
well known, that to the mouth it 1s applied in 
substance and in smoke; and to the nose in the 
form of powder. The opinion which at one time 
prevailed of its power to prolong life and to 
secure immunity from diseases is now pretty 
fully abandoned. It has no prophylactic reputa- 
tion except as a preservation for the teeth, and in 
some degree as a protection against the conta- 
gion of epidemics. In both these cases it is 
entitled to'a certain degree of confidence, though 
