ON LOBELINA. 
5 
a portion of the natural salt of lobelina. The green color of 
the oil is due to chlorophylle, derived from minute portions 
of the leaves of the plant being mixed with the seeds. 
A portion of the seed finely bruised was subjected to pres- 
sure, surrounded by bibulous paper, and the latter, after the re- 
moval of all extraneous matter from its surface, was macerated 
in ether, which was subsequently evaporated. The oil thus 
obtained had very little color, and by exposure becomes lim- 
pid. Its specific gravity is .940°. The most prominent qual- 
ity of this fixed oil is a tendency to the rapid absorption of 
oxygen, and hence it is one of the drying oils. So much is 
this the case, that a portion of oil in a shallow capsule became 
solid in two weeks, and when removed from the vessel had 
the appearance of fragments of gum arabic. A small quantity 
of white paint was prepared with this oil, and it was found to 
dry even more rapidly than linseed oil. The seeds contain 
about 30 per cent, of fixed oil. 
Resin. When a tincture of the seeds made with alcohol 
30° B., is evaporatad, a brown colored substance gradually 
precipitates, which, when dried, has the characters of resin. 
Gum. A decoction of the seed of lobelia is precipitated 
abundantly by subacetate of lead, but is not affected by solu- 
tion of iodine, gelatin, or ferrocyanuret of potassium. 
Lobelic acid. A decoction of the leaves of lobelia is preci- 
pitated dark olive brown by sesquichloride and persulphate 
of iron ; green by sulphate of copper ; deep brown by nitrate 
of silver ; reddish brown by lime and baryta waters, and is not 
affected by pure soda or the chloride of calcium or barium. — 
From the peculiar effects of metallic salts on the decoction, 
Professor Pereira inferred the presence of a peculiar acid 
which he designated lobelic acid, in case future experiment 
should prove its claim to the title. 
One ounce of lobelia leaves in powder was boiled in half a 
pint of water for half an hour ; when cold, the decoction was 
filtered, and sulphate of copper added as long as it caused a 
precipitate. This was collected on a filter and washed with 
water until the washings ceased to taste or evince an acid re- 
