156 Miscellaneous Intelligence. 



readily convertible into it. Fixed alkalies, for instance, exert 

 no action on it when cold, though at high temperatures they 

 readily form prussiates, and a crystalline substance very dif- 

 ferent from that already described. Another acid, and a resi- 

 nous matter, is also found at the same time. 



M. Robiquet, in a note, considers the oil of the cherry laurel 

 as identical with that of bitter almonds. — Ann. de Chim. xxi. 250. 



6. Action of Animal Charcoal in the refining of Sugar. — 

 M. Payen proves, in a memoir which has been rewarded by the 

 Pharmaceutical Society of Paris, 1st, That the decolouring 

 power of charcoal, in general, depends on its state of division; 

 2d, That in the various charcoals, the carbonaceous matter, 

 only, acts on the colouring matters, combining with and precipi- 

 tating them ; 3d, That in the application of charcoal to the re- 

 fining of sugar, it acts also on the extractive matters, for it sin- 

 gularly favours the crystallizati<|p ; 4th, That according to the 

 above principles, the decolouring action of charcoals may be so 

 modified, as to make the most inert become the most active ; 

 5th, That the distinction between animal and vegetable char- 

 coals is improper, and that for it may be substituted that of 

 dull and brilliant charcoals ; 6th, That of the substances pre- 

 sent in charcoal besides carbon, and particularly in animal 

 charcoal, those which favour the decolouring action have an 

 influence relative only to the carbon : they serve as auxiliaries 

 to it, by isolating its particles, and presenting them more freely 

 to the action of the colouring matter; 7th, That animal char- 

 coal, besides its decolouring power, has the property of taking 

 lime in solution from -water and syrup. 8th, That neither ve- 

 getables, or other charcoals besides animal, have the power of 

 taking lime from water or syrup ; 9th, That by the aid of an 

 instrument, which he proposes to call a decolorimeter, it will 

 be easy to appreciate exactly the decolouring power of all 

 kinds of charcoal. — Annates de Chim. xxi. 215. 



7. Refining or tougheniyig of Copper. — When the smelter has 

 reduced his copper perfectly, it is in what is called a dry state. 

 It is brittle, of a deep red colour inclining to purple, an open 

 grain, and a crystal'ine structure. A process is then resorted 

 to, called the poling, the object being to render the copper 

 tough and malleable. The metal, whilst in fusion in the re- 

 verberatory furnace, has its surface covered with charcoal, and 



