268 VINEGAR, CIDER, AND FRUIT- WINES. 



acetate of lead (sugar of lead) with pure carbonate or sulphate 

 of potassium. To detect the presence of lead it should be 

 tested with sulphuretted hydrogen, which in the presence of 

 this metal produces a slightly brown precipitate. To obtain a 

 pure product the decanted liquid is treated with sulphuretted 

 hydrogen, and, after separating from the precipitate and adding 

 a small quantity of acetic acid, is evaporated in a stone-ware 

 vessel. 



Potassium acetate is readily soluble in water and ordinary 

 alcohol ; it is quite soluble in absolute alcohol, but insoluble in 

 ether. It is a very deliquescent salt and difficult to crystallize. 

 The entirely pure salt in dilute aqueous solution should not give 

 precipitates with potassium or with sulphuretted hydrogen, nor 

 with barium chloride or nitrate of silver. 



At an ordinary temperature 100 parts of water dissolve 230 

 parts of the salt ; a saturated solution, which boils at 336.2 F., 

 contains for 100 parts of water 800 of the salt. From the alco- 

 holic solution of the salt potassium carbonate is thrown down by 

 a stream of carbon dioxide. 



Potassium acetate melts without decomposition at 482 F. to 

 an oily liquid, and on cooling forms a crystalline, foliated mass ; 

 at a red heat it is decomposed into acetone, hydrocarbons, empy- 

 reumatic products, and a residue of carbon and potassium car- 

 bonate. 



By the decomposition of acetate of potassium by electrolysis 

 Kolbe first obtained free methyl. 



Potassium acetate, when treated with potassium hydrate in ex- 

 cess, becomes converted into carbonate of potassium and marsh 

 gas. When heated with arsenious acid, cacodyl (Cadet's fuming 

 liquid) is produced. This reaction is so decided, and the allia- 

 ceous odor evolved so strongly marked, that it forms one of the 

 best tests for small quantities of acetic acid. 



Potassium acetate is an important medicine; it is employed 

 as a diuretic; it is also recommended for the preservation of 

 microscopic objects, .and it is occasionally used for the prepara- 

 tion of pear ether (amyl acetate). 



Potassium acid acetate or potassium diacetate, KC 2 H 3 O 2 C 2 H 4 O 2 , 

 is formed by evaporating a solution of the neutral salt in excess 



