390 ODOEOGRAPHIA. 



previously diluted with 2 parts of water. Hydrochloric acid may 

 also be used, but it has the disadvantage of distilling over with the 

 oil. To obtain furfurol in large quantity, Stenhouse mixes 32 

 pounds of wheat-bran with 20 pounds of sulphuric acid diluted 

 as first mentioned, in a capacious 3-necked glazed earthenware 

 Woulfe's bottle (such as are used in the preparation of nitric and 

 hydrochloric acids on the large scale). He then distils by passing 

 steam into the mixture ; neutralises the strongly acid distillate 

 with chalk; rectifies the distillate repeatedly, and separates the 

 oil by saturating the liquid with common salt, and re-distils. This 

 process yields from 12 to 13 ounces of crude furfurol, containing 

 a considerable quantity of acetone. 



Schwanert proceeds in a similar manner,* using 100 pounds of 

 strong sulphuric acid and 300 parts water to 100 parts bran, and 

 obtains 5 parts furfurol, partly directly, partly after conversion 

 into furfuramide by ammonia and subsequent decomposition of 

 that compound by distillation with hydrochloric acid. 



7^ — Bran and chloride of zinc (in the proportion of 3 or 2 J to 

 1) in the state of solution strong enough to form a damp mass 

 cohering in lumps, are distilled together, whereupon water passes 

 over first, then furfurol, then hydrochloric acid, and lastly a solid 

 fatty mass which floats on the surface, consisting of margaric acid 

 and a small quantity of a hydrocarbon. The distillate is strained 

 through linen, neutralised with potash, saturated with common 

 salt, and rectified. The furfurol, after being separated from the 

 water which passes over with it, is dried over chloride of calcium 

 and again rectified. The watery portion of the distillate still 

 contains a little furfurol, which may be converted into furfuramide, 

 as in process 6. Six pounds of bran thus treated yielded from 1 

 to 2 ounces and sometimes more of furfurol. Bran containing a 

 larger proportion of starch yields less.t 



8° — The most abundant and economical source of furfurol is in 

 the preparation of Garancin, by boiling madder with sulphuric 

 acid. If the w^ooden boilers in which garancin is usually 

 manufactured were fitted with condensers, furfurol might be 

 obtained in any quantity without expense. Furfurol is also 



* Ann. Chem. Phaim., cxvi., p. 257. 



t Babo, Ann. Chem. Pharm., Ixxxv., p. 100. 



