324 Intelligence and Miscellaneous Articles. 



before in boiling alcohol, and is deposited in crystals on cooling. 

 At about 374° Fahr. it decomposes, and then yields extremely fetid 

 empyreumatic products, and leaves a very bulky charcoal. These 

 experiments show that crystallized cinchovatina is perfectly anhy- 

 drous. 



By analysis it yielded very nearly, 



(Foreign equivalents.) 



Carbon 69 ; 80 or O 6 = 3450-00 



Hydrogen 6"83 . . H 54 = 337'50 



Oxygen 16.21 .. O 8 *= 800-00 



Azote 7-16 Az 4 = 353-Q8 



100- Equivalent = 3941-50 

 Journ. de Pharm. et de Chim., Aout 1842. 



PREPARATION OF PURE POTASH AND SODA. 

 M. Schubert observes that the mode of preparing caustic barytes 

 from sulphuret of barium, by means of oxide of copper, admits of 

 its being used for the ready obtaining of potash and soda chemically 

 pure. Crystals of neutral sulphate of potash or sulphate of soda are 

 to be dissolved in a concentrated solution of caustic barytes, until 

 chloride of barium shows an excess of these salts in a small quantity 

 of the filtered liquor, then barytes water and a solution of the sul- 

 phates are to be alternately used till neither produces any precipita- 

 tion, and proving that there is neither barytes nor sulphate in excess. 

 It is, however, better to have an excess of barytes than of sulphuric 

 acid, because the former precipitates during evaporation in the state 

 of carbonate ; but then the evaporated alkali must be redissolved, fil- 

 tered, and again evaporated, and these operations necessarily intro- 

 duce a considerable quantity of carbonic acid into the product. — 

 Journal de Pharm. et de Chimie, Aout 1842. 



DETECTION OF IODINE IN BROMIDES. 



The presence of the alkaline iodides in the bromides which are 

 prepared with the bromine obtained from the mother waters of soda, 

 is less rare than is supposed. This fact depends, as chemists well 

 know, on the difficulty found in separating from bromine, which is 

 liquid at common temperatures, the small proportions of iodine, 

 which exist in it in the state of bromide. Various specimens of the 

 bromide of potassium of commerce, which have been offered to M. 

 Lassaigne, constantly contained a very small quantity of iodide, and 

 it is by the very sensible reaction of starch that he has been able to 

 detect it. 



On adding to the solution of bromide of potassium to be examined, 

 a few drops of a weak solution of chlorine, the liquid soon becomes 

 of a yellow colour ; if there then be immersed in it white paper 

 starched, or covered with a mixture of starch and water, and after- 

 wards dried, it becomes of a violet or of a light indigo blue colour. 

 This colour depends on the iodine set free by the first portions of 

 chlorine added to the impure bromide. 



