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XXVI. Note on the Action of Bromine on Acetic Acid. 
By W. H. Perxrn, F.C.S., and B. F. Durpa, Esq.* 
\ a paper upon monochloracetic acid that appeared in your 
Magazine last July, Dr. R. Hoffmann stated that bromine 
does not act upon acetic acid even in the sunlight, which state- 
ment we are happy to confirm; but having by another mode of 
proceeding induced these substances to act on each other, we 
thought it advisable to send in a short account of our results. 
When a mixture of 4 vols. of glacial acetic acid and 1 vol. of 
bromine is heated in a sealed tube to 120° or 130° C., the mix- 
ture becomes colourless, and on opening the tube torrents of 
hydrobromie acid are evolved. The liquid product, when sub- 
mitted to distillation, sometimes commences to boil as low as 
90° C., when large quantities of hydrobromic acid are present, 
and. then gradually rises to 208° C., when the distillate com. 
mences to solidify in the condenser: this substance is bromo- 
acetic acid, C4(H° Br) O*. It crystallizes in rhombohedrons, is 
very deliquescent, and decomposes partially every time it is 
distilled, evolving hydrobromic acid. 
The silver salt was prepared by adding a little carbonate of 
silver to a solution of the new acid to separate any free hydro- 
bromic acid, filtered, and then nearly saturated with carbonate 
of silver, which produced a dense crystalline precipitate ; the 
hquid was then filtered off, the crystalline mass washed with 
cold water and dried in vacuo. An aqueous solution of this salt 
decomposes slowly even at the ordinary temperature, bromide 
of silver being precipitated ; by boiling it is rapidly decomposed. 
The dry salt, on being heated to about 90° C., suddenly decom- 
poses, leaving bromide of silver, together with a substance that 
carbonizes at a higher temperature: it seems to be very hygro- 
metric. A determination of the silver gave 43-61 per cent., 
theory requiring 43:9, 
The lead salt crystallizes in small, brilliant needles, taking 
a slight pink hue if exposed to light; it is very insoluble in 
water, and is decomposed by long boiling into a viscid, uncry- 
stallizable substance. An analysis of this salt gave— 
42°774 per cent. of lead, and 33:1 of bromine; the formula 
C* (H? Br Pb) O4 requires 42°878 of lead, and 31117 of bro- 
mine. 
When a mixture of 1 vol. of phenic acid and 2 vols. of bro- 
moacetic acid is heated in a sealed tube to 130°C. for five hours, 
it becomes brown. This product, when neutralized with potash, 
produces a carmine-coloured liquid, which is the potassium salts 
of two acids ; however, we refrain from giving an account of 
* Communicated by the Authors. 
