Comparative Analysis of the Gum Resins. 345 
species, which grows to the height of 20 fect. The Ezphor- 
lia madagascariensis also yields a juice which the Indians 
thicken, and which they use, instead of our vomiting medi- 
cines, for small-pox with great success, according to Son- 
nerat. Other species might also yield euphorbia; but 
Linnezus observes that the Euphorbia officinarum ought 
to be the only species in use. Upon inspecting a great 
quantity of euphorbia in fine large tears, I accidentally met 
with some branches of the plant itself, which gave ne an 
opportunity of ascertaining and determining the species. 
These branches were rather long, quadrangular, furnished 
with numerous tubercles ranged Jongitudinally, and armed 
at their angles with two black spears short and divergent. 
These characters by no means belong to the Euphorbia 
officinarum, but evidently to the Euphorbia canuriensis, 
which seems to furnish the euphorbia which is brought to 
France. 
The analytical results which the ancients obtained from 
euphorbia are too vague and incorrect to relate them here. 
§ II. The eupborbia which J examined, was in branchy 
cavernous friable tears, of a pale-yellow, and having the 
semi-transparency of wax. This substance is so acrid that, 
having put a small quantity on my tongue,.my mouth was 
inflamed, with anardent inclination to vomit imimediately 
afterwards. 
Euphorbia-when exposed to a gentle heat softens easily, 
and loses ;',th of its weight by evaporation. 1 boiled four 
grammes of euphorbia with 100 grammes of distilled water: 
the filtered liquor left an insoluble matter, which when 
dried weighed three grammes; that which passed over was 
of an amber colour, and had a bitter taste accompanied 
with a slight acrimony. 
This colour reddened turnsole tincture. 
The oxalate of potash produced an abundant sediment of 
oxalate of lime. 
The nitrate of lead. forms a white sediment entirely solu- 
ble in distilled vinegar. 
Lime-water also disturbs this liquor, and produces a yel- 
low precipitate which vinegar dissolves. 
§ III. A. E treated by boiling 20 grammes of euphorbia’ 
with 90 grammes of alcohol at 36°, which was sufficient for 
dissolving all the particles which were suscepuble of solu- 
tion. This solution, being filtered while in. a boiling state, 
left on the filter a substance which was well washed with 
alcohol : this matter when dried weighed 6:4 grammes. 
B. The alcoholic solutions were mixed, and they apogee 
turbi 
