4^6 Miscellaneous Intelligence. 



time, one witli the air removed, the other containing air at the 

 ordinary pressure of the atmosphere ; the i^raduation of the last 

 remained accurate after several months, whilst the zero of the first 

 rose nearly a half degree. The bulb of the altered thermometer 

 was so thick, that no effect due to atmospheric pressure acting 

 from without inwards could be supposed a circumstance which 

 excludes the explanation of the effect adopted by MM. Bellani and 

 Flaugergues. 



M. Arago concludes by ^observing that it may perhaps be found 

 preferable to boil the mercury so well as to exclude all air from it ; 

 but states that from certain experiments made by M. Dulong, and 

 not as yet published, it would appear that the precautions necessary 

 are so minute and numerous, that the instrument-maker will find it 

 a difficult matter to construct a thermometer of that kind that will 

 not change its zero. — Annales de Chimie, xxxiii. 423. 



7. On Bromine and certain of its compounds, by M. Serullas. — 

 According to M. Balard, bromine remained fluid at a temperature 

 so low as 0° Fahr. M. Serullas found that a degree or two below 

 this it suddenly became solid, and was then hard, and so brittle as 

 to break by a blow. 



On adding hydriodide of carbon to bromine in a tube, there was 

 immediate action, much heat, a hissing noise, and a bromide of 

 iodine and a fluid hydro-carburet of bromine were formed ; — a further 

 instance this, of the displacement of iodine by brome. Water dis- 

 solved the bromide of iodine, and the hydro-carburet with a little 

 excess of bromine remained at the bottom of the fluid. It was ren- 

 dered colourless by a little alkali. If the hydriodide of carbon is 

 in excess, but little hydro-carburet of bromine is produced, but a 

 sub-bromide of iodine. 



The pure hydro-bromide of carbon is colourless, heavier than 

 water, of a penetrating ethereal odour, an exceedingly sweet taste, 

 and very volatile. It does not become coloured in the air like the 

 hydriodide of carbon, and when dropped on ignited porcelain it 

 yields white vapours instead of violet. The same compound was 

 formed by placing a drop of bromine in olefiant gas. When this 

 substance is cooled to about 22° Fahr., it becomes solid, and then 

 breaks in the manner of camphor. 



M. Serullas formed hydro-bromic ether by putting forty parts of 

 concentrated alcohol into a retort with one part of phosphorus, and 

 afterwards adding, in small portions, seven or eight parts of bro- 

 mine ; upon each addition there was much action upon the phos- 

 phorus ; heat was evolved, and hydro-bromic and phosphorus acids 

 produced. Then carefully distilling the mixture, and washing the 

 product with water, the hydro-bromic ether was collected at the 

 bottom. It appeared as a colourless, transparent fluid, heavier 

 than water, with a strong and etherial odour, and a sharp taste; it 

 is very volatile, is soluble in alcohol, but is precipitated by water ; 

 it suffers no change of colour 



