II. On the form of crystals of peroxide of benzoyl

The peroxide of benzoyl, C14 H10 O4 , or carbon 69·42, hydrogen 4·13, oxygen 26·45, was discovered by Professor (now Sir B. C.) Brodie, and described by him in the ‘Proceedings’ of the Royal Society, vol. ix. p. 361. The crystals were obtained from a solution in ether of the product of the mutual decomposition of equivalent proportions of chloride of benzoyl and peroxide of barium mixed in water. The faces of the crystals, though brilliant, were not very even, so that, in order to obtain a moderately accurate result, it was necessary to measure a large number of crystals.