252 



VINEGAR, CIDER, AND FRUIT-WINES. 



The results obtained by Assmus in manufacturing on a. large 

 scale are as follows : 



According to Rothe's experience, the trunk-wood of birch 

 from 60 to 80 years old and grown upon a high dry soil with a 

 limestone sub-soil surpasses the best red beech in the yield of 

 acetic acid. He obtained from 100 pounds of this kind of wood 

 dried at 140 to 158 F., with heating for 48 hours, at a final 

 temperature not exceeding 750 F., 40 pounds of wood-vinegar 

 of 25 per cent, acetic anhydride, further 2 or 3 per cent, of tar, 

 and 30 per cent, of red charcoal suitable for the manufacture of 

 powder. 



The yield of salable, though not entirely pure methyl alcohol, 

 is J Ib. and at the utmost 1J Ibs. from 110 Ibs. of wood ; accord- 

 ing to Vincent, 2 to 3 quarts from 35.31 cubic feet. This higher 

 yield is said to be obtained by moistening the wood with soda 

 solution and drying. In case this statement is correct, it would 

 be advisable to saturate saw-dust with soda solution, and after 

 drying distill in Halliday's apparatus.* It consists of a hori- 

 zontal, cast-iron cylinder. The saw-dust, spent dye-wood, etc. 

 are introduced through a hopper placed above the front end. In 

 the cylinder a vertical screw or worm revolves at such a speed as 

 to convey the material in the proper quantities to the cylinder 

 placed in a horizontal position and heated by means of a furnace. 

 Another revolving screw or worm keeps the saw-dust, etc., in- 

 troduced in the retort in constant motion and at the same time 

 moves it forward to the opposite end of the retort. During their 



Muspratt's Chemistry, Vol. I. p. 23. 



