34 



which crystallizes if cooled to 16.5 C. It has a specific gravity of 

 1.0553 at 15 C. and boils at 119 C. 



The ordinary acetic acid of commerce contains about 30 per cent 

 of anhydrous acid, has a specific gravity of about 1.040, and is 

 slightly colored. It is used in the preparation of acetates, the manu- 



FIG. 16. Still for preparing acetic acid from acetate of lime, with detail of acetate pan. 



facture of white lead, and in pharmacy. Some pure acetic acid made 

 from wood by distillation is used as vinegar, but such preparations 

 have not the characteristics of fruit vinegar. 



In addition to acetate of lime and soda already described (p. 32), 

 the following acetates are prepared for industrial purposes : 



[Cir. 36] 



