1907.] 



WILEY AND SCHREIBER— SYNTHETIC ALCOHOL. 



121 



three volumes of sulfuric acid and seven volumes water is converted 

 to acetaldehyde or that approximately 75 per cent, sulfuric acid 

 gives crotonaldehyde, and 42 per cent, sulfuric acid gives acetalde- 

 hyde. These figures assume that Erdmann and Kothner mean 

 H2SO4 1.84 sp. gr. when they say '' concentrated." -The latter also 

 find that addition of mercuric oxid facilitates the process and that 

 phosphoric acid of sp. gr. i. 15 may be used, which they claim gives 

 a purer acetaldehyde than sulfuric acid. 



Apparatus No. 2 was constructed to carry out Erdmann and 

 Kothner's method. The acetylene was again generated in a fruit 

 jar (b) and washed through lead acetate^ (c) then through an empty 

 flask (d) to catch any liquid forced back by back pressure. From 

 here it passed through 3 round bottom Jena flasks (e) (3 liter) con- 

 taining 1500 c.c. sulfuric acid (3 volumes acid, 7 volumes water) and 

 100 grams mercuric oxid. To prevent bumping, glass beads were 

 put in the flasks and the flasks wound with asbestos paper. The 



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flasks rested on shallow sand baths heated by a bunsen burner. Each 

 flask was closed by a rubber stopper carrying a reflux condenser for 

 exit and a i%-inch glass tube reaching to the bottom of the flask 

 for entry of gas. The reflux condensers were fed by warm water 

 ^ " Lehrbuch der anor. Chem.," Erdmann, 4th ed., p. 437. 



