1826.] tontained in Sea Water. 4155 



chlorid^^' br^i^fy ^tim is formed. Iodine does not act upon it^ 

 even at a high temperature ; on the contrary, when brome is 

 made to p&ss over fused iodide of potassium, abundant violet 

 vappurp.are disengaged ; boracic acid does not decompose it at 

 a red hea^, unless the vapour of water be passed over the mix- 

 ture, atid then hydrobromic acid is given out. 



When bromuret of potassium is put into water, it is converted 

 into hydrobromate of potash ; it is more soluble in hot water 

 th^n cold, and produces a sensible diminution of temperature 

 during solution ; it is soluble also in alcohol, though sparingly 

 so ; the solution of hydrobromate of potash does not dissolve 

 more brome than pure water; the solution is decomposed by 

 sulphuric acid, which disengages the vapour of hydrobromic acid, 

 and of brome; 1-27 gramme of brome, treated in this manner, 

 left a residuum of 0*973 of sulphate of potash ; this quantfty of 

 salt contains 0*52668 of potash, consisting of 0*08927 of oxygen 

 and 0*43741 of potassium: according to this experiment, bro mu- 

 ret of potassium is composed of 



3ax8ajsq s; Brome w>j4.#>i*f.>)«» 65*56 



^b.7uoqjiJ.jPotassium . o^wj^ »^^ff> >•,» ^r,i?j^... -r. ; • . 34*44 



8§^^iiirig this compound td be'^otmed of an atom of brome and 

 'an atom of potassium, the atomic weight of brome will be 93*26, 

 the atom of oxygen being 10. . =,' 



The metallic bromurets are converted into neutral hydrobrpf 

 tnates by solution in water, which, being decomposed, the two 

 volumes of hydrogen combine with the brome, and the volume 

 of oxygen unites with the metal. As hydrobromic acid is comr- 

 posed of equal volumes of hydrogen and the vapour of brome, it 

 follows that the two volumes of hydrogen should produce four 

 volumes of hydrobromic acid ; from which it is to be concluded 

 that the metallic hydrobromates contain in volume four times 

 as much hydrobromic acid as of oxyg-^n in their oxides ; then 

 as 0*08927 gramme of oxygen occupies a volume of 0*0624 lit. 

 1*270 gramme of bromuret of potassium ought to yield 0*2496 lit. 

 of hydrabromic acid. The specific gravity of the vapour of 

 "brdnie according to these data ought to be 5*1354, and that of 

 bromic acid 2*6021. I have not yet verified these theoretical 

 results by experiment. 



i'one ^ifiiimr- Hydrohr ornate of Ammonia. 



' If yd?6bromic acid gas combines with an equal volume 6f 

 ammoniacal gas; the result is a saline compound which may 

 also be obtained by combining hydrobromic acid with liquid 

 ammonia. I have already prepared hydrobromate of ammonia 

 by decomposing ammoniacal gas, or liquid ammonia with 



