442 Miscellaneous Intelligence, 



Protosulphate of Iron — 100 gave, when heated, 55.25 not quite 

 anhydrous ; these absorbed 52.75 in 14 days. 



Sulphate of Cadmium — 25 p. absorbed 35 in 220 days. 



Sulphate of Zinc — 100 gave 64 by heat ; these absorbed 39.8 in 

 21 days. 



Acetate of Zinc — 100 lost 23 by heat; the 77 parts absorbed 

 23.7 in 19 days.— Jahrb, der Phys. 1827, p. 420. 



27. On the Production and Nature of Alcoates. — Mr. Graham has 

 formed, analyzed, and described a class of bodies which he has named 

 alcoates, from their analogy to hydrates. They perfectly resemble the 

 latter bodies, except that they contain alcohol, instead of water. The 

 alcoates obtained were not numerous, and were formed simply by 

 dissolving the salts constituting their base, and previously rendered 

 anhydrous in absolute alcohol, with the assistance of heat. On 

 cooling, the alcoates were deposited in the solid state. The crystal- 

 lization was generally confused, but in some cases crystalline forms 

 appeared of a singular description. The crystals are transparent, 

 decidedly soft, and easily fusible by heat in their alcohol of crystal- 

 lization, which is generally considerable. 



Alcoate of Chloride of Calcium. — Chloride of calcium, as is well 

 known, dissolves in abundance in alcohol ; it furnishes one mode, 

 and perhaps the best, of separating alcohol and ether in analytical 

 investigations. To obtain the alcoate, 1 part of the chloride is to be 

 dissolved in 5 parts of alcohol ; the solution filtered whilst hot, and 

 then concentrated by heat until it is thick and viscid : being then 

 left to cool, crystalline plates appear on the surface of the solution, 

 and sides of the vessel ; they are always small, often delicately stri- 

 ated, and of the form of an isosceles triangle. These are frequently 

 grouped together. They cannot be removed uninjured, because of 

 their softness ; they deliquesce in the air, and melt by the heat of 

 the hand. The whole of the alcohol is expelled by a heat of 250®. 



A portion being dried by pressure between linen, and then be- 

 tween bibulous paper, resembled bleached wax. Being decomposed 

 by heat it appeared to consist of 



2 proportionals chloride of calcium, 14. 

 7 proportionals of alcohol, 20.125. 



Mr. Graham found that when water was present, chloride of cal- 

 cium would retain alcohol even at temperatures of 400° or 500°, for 

 several hours. 



Alcoated Nitrate of Magnesia. — Nitrate of magnesia is to be ren- 

 dered anhydrous in a glass tube by the heat of a spirit lamp, and then 

 dissolved in boiling absolute alcohol. 1 part of the nitrate dissolves in 

 4 parts of alcohol, at 60° ; in two parts when boiling : the magnesia 

 from that part of the nitrate decomposed during the desiccation is left, 

 and must be separated by filtration or decantation. The most con- * 

 venient proportions are 1 to 3. The great proportion of crystalline 

 matter is obtained as a mass of scales, of a pearly lustre and white- 

 ness, apparently made up of small crystals. Being dried as before, 



