154 Scientific Intelligence. — Chemistry. 



bromide of calcium remains. Acids disengage bromine. In a word, 

 it has all the characters of chloride of lime. 



Preparation of bromine. — The mother waters which contain it are 

 reduced to a quarter of their volume in iron pots and left several days 

 in repose, during which the greater part of the chloride of calcium crys- 

 tallizes. The supernatant liquid, after dilution with water, is mixed 

 with sulphuric acid as long as a precipitate ensues. The supernatant 

 fluid is then decanted, and the residuum is subjected to pressure. 

 All the fluids are united, evaporated to dryness, and the residue dissol- 

 ved in order to separate a certain quantity of sulphate of lime. The 

 bromine is obtained by treating the solution vsdth sulphuric acid and 

 peroxide of manganese. — Ann. de Chim. Oct. 1829. 



19. Preparation of hromine hy M. Hermann from the mother water 

 of the salt spring of Schonebeck. — Twenty pounds of the mother water, 

 much concentrated, are distilled with twenty pounds of sulphuric acid 

 of a density about 1.520 the product is about fifteen pounds ofhydro- 

 cloric acid. This product saturated with chalk, is decomposed by 

 sulphate of soda. The liquid separated from the sulphate of lime, 

 is concentrated, and the supernatant mother water is treated with sul- 

 phuric acid and peroxide of manganese. JYothing but chlorine is 

 disengaged. 



The fluid remaining in the retort, after the distillation of the hy- 

 drocloric acid, and which contained a great excess of sulphuric 

 acid, is saturated with carbonate of magnesia, and the magnesian salt 

 thus formed is separated by crystallization. The remaining mother 

 water, treated like the preceding, gives immediately a considerable 

 quantity of bromine. — Idem. 



20. Preparation of ioduret of azote, by M. Serullas. — ^^Saturate 

 alcohol at 33° with iodine, filtering or decanting to separate some im- 

 purities, which are always present, and adding liquid ammonia in 

 great excess, stirring the mixture with a tube. Dilute with water, 

 and by repose the ioduret is- deposited, so that with care the liquid 

 can be decanted off to the last portion. Wash the remainder well 

 with water and the ioduret remains in the form of a fine powder. 

 The washing by decantation is most convenient, but it is sometimes 

 necessary to finish with the filter, because the ioduret being extreme- 

 ly divided, a portion of it is very slowly deposited. 



This modification of the process is considered as stated by the 

 author to be incomparably superior to the ordinary, especially as it 



