100 ODOROGRAPHIA. 
to repeated fractional distillation in vacuo. The fraction boiling 
between 135° and 145° (at 11 mm. atmospheric pressure) has been 
found to consist entirely of this ether. The cinnamic alcohol 
obtained by saponification crystallizes from ether in white solid 
rystals. 
When rectified oil of cajeput, the fraction boiling between 174° 
and 178° C., which forms three-fourths of the crude oil and is 
cajuputene dihydrate, C,)H),+2H,0, is cohobated with phosphoric 
anhydride for half an hour and distilled, there passes over between 
160° and 165° the hydrocarbon Cajuputene, C,)H,., which is a 
colourless liquid possessing the odour of hyacinths ; it is insoluble 
in alcohol but soluble in ether and in oil of turpentine. Its sp. gr. 
at 15°C. is 0°850. It is permanent in the air. 
The perfume of hyacinth is also remarkable in Benzyl alcohol 
(Hydrate of Benzyl), C;H;0. Benzyl alcohol is formed by the 
action of sodium amalgam and water on benzaldehyde *, and on 
benzoic acid. Benzoyl chloride is also reduced to benzyl 
alcohol by the action of sodium amalgam and hydrochloric acid { ; 
it is also yielded in large quantity by adding sodium amalgam to 
an ethereal solution of benzamide which contains water and has 
been rendered faintly acid with hydrochloric acid §. It is most 
easily obtainable from benzyl chloride (which can readily be 
prepared from toluene) by boiling it for two hours with water and 
lead hydroxide ||, or by simply boiling it for two days with 25 to 
30 parts of water §. Mennier states ** it may be advantageously 
prepared by boiling equal parts of benzyl chloride and potassium 
carbonate with 10 parts of water for several hours. If 10 parts 
of benzaldehyde be shaken up with a solution of 9 parts of caustic 
potash in 6 parts of water until a permanent emulsion is obtained, 
and sufficient water to form a clear solution be then added to the 
semi-solid mass of crystals formed on standing by the separation 
of potassium benzoate, the benzyl alcohol can readily be extracted 
from the liquid with ether. The ether is then distilled off and the 
residue purified by rectification without being dried; 92 per cent. 
of the theoretical yield can thus be obtained. As only one half 
* Ann. Chem. Pharm. exxiv. p. 324. t Ibid. exxxii. p. 75. 
{ Ibid. cxxxvii. p. 252. 
§ Ber. Deutsch. chem. Ges. vil. p. 1462. 
|| Ann. Chem. Pharm. exliii. p. 80. q Ibid. cxevi. p. 353. 
** Bull. Soc. Chim. xxxviii. p. 159. 
