YLANG-YLANG. 121 
bisulphite is without action upon this oil. Potash, on the con- 
trary, when sufficiently concentrated and used at a suitable tempe- 
rature, gives rise to a kind of saponification. If the alkaline 
portion be removed and a fresh quantity of potash added, and the 
treatment be repeated until the oil is no longer attacked, a sub- 
stance is left which is insoluble in water. The aqueous portion 
upon the addition of hydrochloric acid deposits a solid body having 
a crystalline aspect. This dissolves with facility in boiling water ; 
the solution, being filtered to separate a small quantity of resinous 
matter, yields upon cooling white pearly plates. This body melts 
at about 120° C.; it volatilizes very readily, and is deposited upon 
the cool sides of the vessel in shining needles ; it boils regularly at 
about 245° C. These are the physical characteristics of benzoic 
acid, and this substance has also its chemical properties. In fact, 
if a small quantity be heated in presence of an excess of lime, an 
oil is separated which is insoluble in water and possesses the odour 
and properties of benzene. Treated with perchloride of phos- 
phorus an energetic reaction takes place, and the piquant and 
characteristic odour of chloride of benzene becomes manifest. A 
few drops of this latter body with alcohol yielded benzoic ether. 
For greater certainty Gal submitted some of this acid to analysis. 
0:276 of matter, ignited with oxide of copper, gave 0°126 of water 
and 0°696 of carbonic acid. 
Found. Calculated. 
Cy. e. ooyr 68°8 
| theta te 50 49 
“ Tt is therefore quite evident that the acid abstracted from the 
oil by saponification is none other than benzoic acid. 
“The part insoluble in potash was distilled with water and then 
separated from the water in the distillate. After drying over 
ealcium chloride this oil distilled at about 170° C. to 300° C., very 
nearly as the primitive oil. With so great a range of temperature 
it was useless to expect to separate from this matter definite 
products with a constant boiling-point ; Gal therefore attempted 
to ascertain the nature of these bodies, which might be supposed 
to consist of hydrocarbons analogous to those so often met with in 
oils. The product was treated with phosphoric anhydride; a 
vigorous reaction took place and a liquid was collected which no 
longer possessed the odour of the essence. Iodide of phosphorus 
