270 Mr. Graham's Account of the Formation of Alcoates. 



servation of this fact to attempt the formation of analogous 

 compounds of alcohol and salts, — to which I now proceed. 



These solid compounds of salts and alcohol, which are de- 

 finite and imperfectly crystallizable, may be denominated Alco- 

 ates, — a designation which is not unexceptionable, but ap- 

 peared to me preferable to the name Vinates, as there is a 

 sulpho-vinous acid ; or to any other name that might have been 

 imposed upon them. 



The alcoates which I succeeded in forming are not nu- 

 merous. They were formed simply by dissolving the salts, 

 previously rendered anhydrous, in absolute alcohol, with the 

 assistance of heat. On cooling, the alcoates were deposited 

 in the solid state. The crystallization was generally confused, 

 but in some cases crystalline forms appeared of a singular de- 

 scription. The crystals are transparent, decidedly soft, and 

 easily fusible by heat in their alcohol of crystallization, which 

 is generally considerable, amounting in one instance to nearly 

 three-fourths of the weight of the crystals. 



I. Alcoate of Chloride of Calcium. 



Pure muriate of lime was dried as much as possible on a 

 sand-bath of the temperature of 600° or 700°, and then slowly 

 heated to redness, and retained for some time at that tempera- 

 ture. The dry chloride of calcium thus obtained dissolves in 

 absolute alcohol at 60° with great facility, and with the pro- 

 duction of much heat, sometimes occasioning the boiling of the 

 solution. The quantity of chloride taken up increases with the 

 temperature; and at 173°, the boiling point of alcohol, 10 parts 

 alcohol dissolve 7 parts chloride of calcium. This solution is 

 thick and viscid, but perfectly transparent, provided the chlo- 

 ride be pure. It boils at 195°, alcoholic as well as aqueous 

 solutions boiling at higher temperatures than the pure liquids. 

 The viscidity of the solution of chloride of calcium increases 

 greatly as it cools. Bright crystalline stars soon appear on the 

 surface and on the sides of the vessel, which have been moist- 

 ened by the solution. The solution, however strong, never 

 crystallizes instantaneously, but gradually, in thin transparent 

 and colourless plates, the forms of which cannot be made out, 

 except on the surface of the solution and sides of the vessel. — 

 To obtain the alcoate in a state of absolute purity, it is neces- 

 sary to form a solution so weak, that, while hot, it will pass 

 through thin filtering paper; and afterwards to concentrate 

 the filtered solution by heat. A solution of one part chloride 

 of calcium in five parts alcohol passes through the filter. It 

 is remarkable that the most distinct crystalline forms are not 



obtained 



