48 HAMILTON ON THE FORMATION OF CARBON ETC. VlI.-Note on the Forn7ntion qf Carbon Tetrabromide iri the Manufacture of BronJne. By J. C. HAMILTON Student in the Porkshire College Leeds. A QUASTITY of a white crystalline substance which had been obtained as a residue after the distillation of a quantity of commercial bromine was given to me by Professor Thorpe with the request that I would ascertain its nature and composition. From its physical properties Dr. Thorpe was of opinion that i t was carbon tetrabromide a suppo-sition which my analysis *has confirmed. It had the characteristic smell of this compound melted a t 90*1" and solidified at 88.6'. Recrystallisation from alcohol made no. appreciable alteration in the fusing point. Boiled with an alcoholic solution of soda it was a t once decomposed with formation of a white precipitate of sodium bromide, which readily dissolved on addition of water. On acidulating the liquid with nitric acid and adding silver nitrate silver bromide wa4 formed. An analgsis made by means of this decomposition yielded the following results :-0.3424 gram gave 0.7754 AgBr and 0.0036 Ag = 97.1 per cent. Br. Carbon tetrabromide contains 96.4 per cent. Br. The formation of this body in the manufacture of bromine has not hitherto b e e ~ noticed. It is probably formed by the action of the halogen on the organic matters derived from the sea-weed from which the bromine made in this country is procured