190 ODOROGRAPHIA. 
dilute potash and distilled. The distillate is agitated with a warm 
solution of acid sodium sulphite of sp. gr. 1°25, and the crystalline 
compound thus formed is collected on a funnel, thoroughly washed 
with alcohol, dissolved in as little luke-warm water as possible, and 
the solution heated with excess of strong sodic carbonate, when 
the hydride of anisyl (anisic aldehyde) separates out and floats on 
the surface. It is then purified by redistillation. Itis a yellowish 
liquid of sp. gr. 1:09 at 20°C. Its boiling-point is 253° to 255° C. 
It is almost insoluble in water, but soluble in all proportions in 
alcohol and ether. When exposed to the air, it gradually absorbs 
oxygen and is converted into anisic acid. It possesses the property, 
peculiar to aldehydes, of forming crystalline compounds with the 
acid sulphites of the alkali-metals. 
Rossel prepared anisic aldehyde by oxidizing oil of anise with 
chromic acid *. 300 grams of strong sulphuric acid and 850 grams 
of water are poured upon 200 grams of potassium dichromate ina 
capacious flask ; 100 grams of oil of anise are added after the 
liquid has completely cooled, and the whole is vigorously shaken, 
the temperature of the mixture rising to 70°-80°. When the 
reaction is complete, the liquid is diluted with water to one and a 
half times its volume and distilled, warm water being added through 
a funnel-tube to replace that which distils off. In this way a 
quantity of anisic aldehyde is obtained equal to 50 per cent. of the 
oil of anise used, together with 10 per cent. of anisic acid. Ac- 
cording to Rossel, pure anisic acid boils at 247°-248° C. under a 
pressure of 733°5 mm. (?) and has a density of 1°228 at 18° C. 
* Ann. Chem. Pharm. cli. p. 25. 
