104 
ORIGINAL COMMUNICATIONS. 
raised the colour deepened and the acrimony diminished 
until when boiled it possessed less of the latter than either 
of the infusions. The increments of heat were ascertained 
by a thermometer suspended in the liquid during the opera- 
tion. 
Experiment 4. — A saturated tincture was submitted to 
distillation in a glass retort. The product was colourless, 
having the odour of the tincture without its acrimony, and 
upon evaporation yielded no residuum. It was probably al- 
cohol holding a portion of a volatile oil in solution. 
Experiment 5. — Another portion of the plant was subjected 
to distillation, in a metallic still, with sufficient water to pre- 
vent empyreuma: the distilled liquor had a strong odour of 
lobelia, but was void of taste. This was returned into the 
still and another portion of the plant added, and again drawn 
over. — The last product had a more powerful aroma, from 
which circumstance, the presence of a minute portion of 
volatile oil may be suspected. 
Experiment 6. — Half a pound of the green plant was digested 
in one pint of water, acidulated with one drachm of sulphuric 
acid for four days; then decanted, saturated with magnesia, 
and filtered. The infusion thus obtained had a very acrid 
taste, and was of a dark red brown colour. This was submit- 
ted to distillation in a retort by the aid of a sand bath. The 
product had a strong odour of the plant, but was perfectly 
tasteless, and upon examining the liquid remaining in the 
retort, it had no acrimony except that which was given to it 
by the sulphate of magnesia, resulting from the saturation. 
This experiment was repeated, except that hydro-chloric acid 
was substituted for the sulphuric, with a like result. 
Experiment 7. — A saturated tincture, made with alcohol 
at forty Baume, was precipitated greenish white, upon the 
addition of water, and had the properties of a resin. 
Experiment S. — Dry lobelia was submitted to the action 
of sulphuric ether, at sixty Baume, for twenty-four hours, 
which, upon decantation, and evaporation, yielded a dark 
green viscid mass, which was treated with alcohol to remove 
