52 
SELECTED ARTICLES. 
III. 0.581 grammes gave 0.581 grammes water, and 1.729 
grammes carbonic acid. 
Its composition is, therefore: 
1st 2d. 3d. 
Carbon, 83.25 82.85 82.29 
Hydrogen, 11.35 11.24 11.11 
Oxygen, 5.41 5.91 6.60 
The result of the first experiment accords very well with 
the composition of a combination composed like the previously 
described resins, except that it shows one-half less of oxygen. 
Its true composition would be, carbon 83.61, hydrogen 10.91, 
oxygen 5.47. This might be expressed by the formula 2 (10 
C + 16H) + 0. This formula would also express that this 
resin is a lower degree of oxidation of the radical, the higher 
being the acid resins. 
Crystalline Resin of Euphorbia. — This is prepared in the 
same way as the former, but cannot be procured of as white a 
colour. The form of the crystals is indeterminate. 
It is more soluble in alcohol than the resin of elemi; this 
solution has very little acridity. It has no effect on litmus pa- 
per; it does not become opaline on the cooling of the solution, 
but the resin separates in the form of groups of mammillary 
crystals. Ammonia produces a white cloud, but the resin 
does not separate in a gelatinous state, like that of elemi; it is 
not affected by an alcoholic solution of potash, or even an 
aqueous one of this base. Solutions of acetate of lead and ni- 
trate of silver do not cause any precipitate. 
On distillation, this resin comports itself like that of elemi, 
the brown balsam obtained by this operation reddens litmus 
paper. 
Its composition, ascertained by burning it with oxide of 
copper, is: 
Carbon 81.58 
Hydrogen 11.34 
Oxygen 7.07 
