78G ETHYL AND ACETYL. 



much used in dyeing. This salt is decomposed in drying, or by 

 a slight heat, into free acetic acid and a subacetate of alumina 

 which is insoluble. The solution of the pure salt may be boiled 

 without decomposition, but if sulphate of potash, or any other 

 neutral salt of an alkali be present, the solution becomes turbid 

 when heated, and a basic salt precipitates, which dissolves again 

 on cooling (Gay-Lussac). Acetate of manganese is used in dye- 

 ing, and is prepared for that purpose by mixing acetate of lime 

 with sulphate of manganese. This salt is crystallizable. Ace- 

 tate of zinc crystallizes with 3 atoms of water. Acetates of iron : 

 a mixture of the acetates of protoxide and peroxide of iron, 

 employed as a mordant for dyeing black, is prepared directly by 

 dissolving old iron hoops, &c. in crude wood vinegar, with access 

 of air. The ace fates of lead have already been described (page 

 594) ; also the acetates of copper (page 584), acetate of black 

 oxide of mercury (page 653), and acetate of silver (page 

 673). 



SECTION IV. 



PRODUCTS OF THE ACTION OF CHLORINE, BROMINE, AND IODINE 

 UPON ETHYL, ACETYL, AND THEIR COMPOUNDS. 



Oxichloride of ethyl, C 4 H 3 C1 2 O,(1), is an oily colourless 

 liquid, obtained by saturating anhydrous ether with dry gaseous 

 chlorine, cooling the mixture at the beginning, and heating it 

 towards the end of the operation. As in the formation of acetic 

 acid, 2 atoms of hydrogen are oxidated and withdrawn by 

 the action of the oxygen of the air upon alcohol, and re- 

 placed by 2 atoms of oxygen, so in the action of chlo- 

 rine upon alcohol, a similar change occurs, of which the 

 product is the oxichloride of acetyl. When heated with 

 potassium, this compound gives chloride of potassium, and 

 a gaseous body, containing only half the chlorine in the original 

 substance, or C 4 H 3 C1O, (2), observed by Malaguti. By the 

 action of chlorine upon the vapour of pure ether in sun-shine 

 Regnault obtained another crystalline compound C 4 C1 5 O, (3), 

 in which the whole hydrogen of ether is replaced by chlorine. 

 Felix d'Arcet has also observed an accessory product in the 



