138 Chr. Phil. Pruckner on the [Aug, 



following characters : It must, before cooling, be brittle, 

 easily crumbled between the fingers, mixed with blackish 

 carbonaceous points or streaks, between which appear white 

 pieces of dry salt. A solution of the comminuted salt, in 

 four or six times its volume of hot water, possesses a yel- 

 lowish brown colour with a dark tinge, while previously 

 it had a reddish brown colour. 



When the heat is increased towards the end of the pro- 

 cess, as described, care must be taken to do it gradually, 

 so that no smoke shall rise from the acetate, because it 

 might thus be decomposed. Neither must any spark be 

 permitted to come in contact with the acetate of lime ; 

 because, like sugar of lead, it possesses the property, in 

 these circumstances, of catching fire and burning, by which 

 the whole dry preparation would be completely destroyed. 

 The treatment of the acetate of lime in this manner, by 

 means of gradual drying, as experience has shewn, possesses 

 many advantages over the method of drying the salt in an 

 open vessel, because there is no loss of acetic acid, as always 

 occurs by the latter process. The operator has the prepara- 

 tion completely in his power, and with little expense of 

 fuel and time, many hundred weights of salt can be pre- 

 pared at once. 



This process does not merely extend to the removal of 

 the moisture from the acetate of lime, but a chemical in- 

 fluence is exerted by means of it. Because, it is certain 

 that the substances formed by dry distillation, which have 

 been recently distinguished by Reichenbach, are partly 

 dissipated by the heat, and partly decomposed ; the acetate 

 of lime possessing very different properties before and 

 after the process. After the process the salt does not 

 imbibe water so readily as it did previously. After solution, 

 filtration and evaporation, a much purer product is ob- 

 tained than before, and upon the filter a resinous matter 

 remains, the constituents of which have not yet been ex- 

 amined. After the completion of the previous steps the 

 operator proceeds to the next, the 



Separation of pure Pyroligneous and Acetic Acid. — Into a 

 cast iron retort, capable of holding 30 measures of water, 

 (of 2 lbs. Vienna weight), introduce 20 lbs. (Vienna weight) 

 of dry acetate of lime, and then 5 lbs. of water, and stir the 



