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X. An Account of the Formation of ALCOATES, Definite Com- 

 pounds of Salts and Alcohol analogous to the Hydrates. B y 

 THOMAS GRAHAM, Esq. M. A. 



(Read nth December 1827.) 



JN determining the solubility of salts and other bodies in alco- 

 hol, it is desirable to operate with a spirit wholly free from water. 

 But anhydrous or absolute alcohol is formed with difficulty, even 

 by the most improved process that of RICHTER. In rectifying 

 alcohol from chloride of calcium, as recommended by RICHTER, 

 I have never obtained it under the specific gravity 0.798 at the 

 temperature of 60, by a single distillation ; but upon rectifying 

 this product again from new chloride of calcium, I generally 

 succeeded in reducing it to 0.796, which is the specific gravity 

 of the standard alcohol of that chemist. The following experi- 

 ment illustrates this process. 



Four measures of alcohol of the specific gravity 0.826 were 

 poured into a retort, and a quantity of well dried chloride of 

 calcium, amounting to three-fourths of the weight of the alcohol, 

 gradually added with occasional agitation. Much of the salt was 

 dissolved with the evolution of heat ; and the combination was 

 promoted by boiling the whole for a few minutes, the vapour 

 being condensed in the neck of the retort, and returned to the 

 solution. A receiver was then adjusted to the mouth of the re- 

 tort, and the distillation conducted so slowly that the alcohol 

 was condensed entirely in the neck of the retort, and fell drop 

 by drop into the receiver, nearly two seconds elapsing between 

 the fall of each drop. The first measure of alcohol which came 



