3.88 ODOROGRAPIIIA. 



employed, but not so advanta^t^^eouslv as sulphuric acid, as this last 

 does not distil over with the furfurol. 



The researches of Yoelckel* show that furfurol is also present in 

 the oily bodies formed during the dry distillation of sugar. 



The preparation of Furfurol has been described in several ways, 

 as follows : — 



1© — One part of sugar is distilled with 3 parts of manganese, 3 

 parts of oil of vitriol and 5 parts of water ; the formic acid in the 

 distillate saturated with carbonate of soda, the liquid re-distilled, 

 the distillate saturated with chloride of calcium, and lastly, the 

 Furfurol distilled off (Doebereiner). 



2^ — One part of wheat-flour or sawdust is distilled with 1 part 

 oil of vitriol diluted with an equal bulk of water in a copper still, 

 which may be half tilled with the mixture ; the distillation being 

 continued till the residue begins to char ; the distillate, together 

 with about as much water as was at first used, poured back into the 

 still ; the liquid redistilled nearly to dryness ; the formic and 

 sulphuric acids in the distillate (which is rendered milky by the 

 furfurol held in suspension), saturated with potash ; the resulting 

 distillate mixed with a large quantity of chloride of calcium and 

 partially distilled, and this process repeated if necessary, till the 

 greater part of the oil, which is surmounted by an aqueous solution 

 of itself, is obtained in a free state. By this means 100 parts of 

 flour yield 0-52 parts of furfurol. f 



oo — ^^Q parts of oatmeal are heated with 2 parts of water and 

 1 part of oil of vitriol in a still, and the mixture well stirred till 

 the pasty mass has Ijecome liquid from formation of dextrin ; the 

 liquid is then distilled : 1 part more of water is added as soon as 

 sulphurous acid begins to escape ; the distillation is continued till 

 sulphurous acid comes off in large quantity ; the whole distillate is 

 then poured back into the still ; half of it distilled off, and this 

 half neutralised as in process 2, with potash, &c.^ 



40 — One kilo of bran, 1 kilo of water, and half a kilo of 

 concentrated sulphuric acid is introduced into a spacious retort and 

 warmed until it becomes quite fluid ; then having luted en the 



* Ann. Chem. Pharm., Ixxxv., p. 61. 



f Stenhouse, Ann. Chem. Pharm., xxxv., p. 301 ; Ixxiv., p. 278. 



:;: Fownes, ibid, liv., p. 52. 



