MANUFACTURE OF WOOD-VINEGAR. 251 



of January) and only those of nearly the same growth were 

 chosen. From Stoltze's table the following figures for the most 

 important varieties of wood have been calculated : 



or, 



1 cubic metre (35.31 cubic feet) = 750 pounds of birch, yields 

 333 pounds of wood- vinegar of 20 per cent. = 66.6 pounds of 

 acetic anhydride; further, 64 pounds of tar, 181 pounds of char- 

 coal, and 73 cubic metres (2578.06 cubic feet) of gases. 



1 cubic metre (35.31 cubic feet) = 850 pounds of beech, yields 

 371 pounds of wood-vinegar of 19.6 per cent. = 72.7 pounds of 

 acetic anhydride, 80.7 pounds, 207.4 pounds of charcoal, and 85 

 cubic metres (3001.86 cubic feet) of gases. 



1 cubic metre (35.31 cubic feet) = 950 pounds of hornbeam, 

 yields 402 pounds of wood-vinegar of 18 per cent. = 72.3 pounds 

 of acetic anhydride, 105 pounds of tar, 225 pounds of charcoal, 

 and 94 cubic metres (3311.8 cubic feet) of gases. 



1 cubic metre (35.31 cubic feet) = 850 pounds of oak, yields 

 367 pounds of wood-vinegar of 18 per cent, = 66 pounds of 

 acetic anhydride, 77.8 pounds of tar, 223 pounds of charcoal, and 

 86 cubic metres (3037.17 cubic feet) of gases. 



1 cubic metre (35.31 cubic feet) = 650 pounds of fir, yields 271 

 pounds of wood-vinegar of 10.1 per cent. = 27.4 pounds of acetic 

 anhydride, 72.6 pounds of tar, 138.5 pounds of charcoal, and 80 

 cubic metres (2825.28 cubic feet) of gases. 



Gillot has confirmed Stoltze's statements in so far as he found 

 that, in manufacturing on a large scale, with slow and carefully- 

 conducted carbonization and a distilling period of 72 hours, 7 to 

 8 per cent, of the (hard) wood of acetic anhydride can be ob- 

 tained. 



