374 PROFESSOR A. CRUM BROWN AND DR JAMES WALKER ON THE 



and 270°, was converted into the calcium salt in order to purify it. Its quantity was 

 small, and the acid reobtained from the calcium salt was still yellowish and probably not 

 quite pure. On combustion the acid gave the following numbers : — 



0'1881 gramme substance gave 0'4755 gramme C0 2 , and 01785 gramme H 2 0. 



Calculated for C 9 H 1C 2 . Found. 



C 69-23 68-94 



H 10-26 1054 



These numbers do not, indeed, agree very accurately with the formula C 9 H 16 2 , but 

 this is not surprising, as the acid was obviously not quite pure. The acid united slowly 

 with bromine at the ordinary temperature. 



The formation of the ether of the acid may be represented by the following equa- 

 tion : — 



2C 2 H 5 OOC-(CH 2 ) 6 -CH 2 -CH 2 -COO- =C 2 H 5 OOC-(CH 2 ) 6 -CH: CH 2 

 + C 2 H 5 OOC : (CH 2 ) 6 -CH 2 -CH 2 -COOH + C0 2 . 



The acid is certainly unsaturated, and is a normal product of the electrolysis. Its 

 specific gravity at 15°'5 is 0'9240 compared with water at 4°. It is very sparingly 

 soluble in water, readily soluble in alcohol and in ether. 



The alkali salts of the acid are soluble in water. When the aqueous solution of the 

 ammonia salt is evaporated, it gradually loses ammonia, until a viscid salt is left, sparingly 

 soluble in water. A strong aqueous solution of the neutral ammonia salt gives the 

 following reactions, with various metallic salts : — 



No precipitate. 



Flocculent precipitate soluble in boiling water. 



Magnesium sulphate, 

 Calcium chloride, 

 Strontium chloride, . 

 Barium chloride, 

 Zinc sulphate, 

 Mercuric chloride, 

 Lead chloride, 

 Copper acetate, 

 Ferrous sulphate, 

 Ferric chloride, 

 Silver nitrate, 



Gelatinous precipitate insoluble. 



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Crystalline (?) precipitate insoluble. 

 Green flocculent precipitate insoluble. 

 Red-brown precipitate insoluble. 

 Light-brown precipitate insoluble. 

 Flocculent precipitate insoluble, does not blacken on boiling. 



The barium in the barium salt was determined with the following result : — 

 02106 gramme of the salt dried at 130° gave 0'1085 gramme BaS0 4 . 

 Calculated for Ba (C 9 H 16 2 ) 2 . Found. 



Ba 306 303 



The chief product of the electrolysis of ethyl-potassium sebate, working at the lowest 

 possible temperature (40°), and with concentrated solutions, is n-dicarbodecahexanic ether, 

 the ether of sebacic acid itself, and in quite subordinate quantity the ether of the 

 unsaturated acid CH 2 : CH(CH 2 ) G *COOH. The proportions in which these ethers occurred 

 varied with the concentration, &c, but we always found the order the same. The forma- 

 tion of dicarbodecahexanic ether and that of the ether of the unsaturated acid take place 



