DENTAL HOSPITAL OF EXETER. CASES TREATED FROM JUNE 14TH TO SEPTEMBER 30TH, 1880. { Children under 14 309 Extractions. { Adults 641 { Under Nitrous Oxide and Ether 29 Gold Stoppings 45 White Foil ditto 37 Plastic ditto 127 Miscellaneous cases 129 ————— Total 1,317 ————— HENRY BROWNE-MASON, _Hon. Sec._ White Nickel Bronze. The pure white tint of nickel, its inoxidisability, and, therefore, the ease with which it is kept clean, have caused it to come into general use for metal fittings, especially those of vessels and carriages, as well as for the bright parts of engines and machines. But, on account of the relatively high price hitherto obtained by nickel, it has been employed chiefly in the state of electro-deposit. Nickel-plating is effected by two processes, one hot and the other cold. In the former a solution of sulphate of nickel is used in an enamel cast-iron trough. This is the more rapid method, but its results are not so satisfactory as in the cold process. The latter is effected with a bath of double sulphate of nickel and ammonia, the articles to be nickelised being suspended by a platinum wire attached to the positive pole of the battery, while a plate of pure nickel, to restore the metal to the bath, is put in connection with the negative pole. The nickelisation thus produced, though it requires a longer time than the other process is finer and more durable. There are, however, several objections to nickel-plating. The process is injurious to the workmen engaged in it. The thin coating of nickel is liable to peel off, and in the case of parts exposed to wear, or even with cleanings, in course of time, the nickel becomes so worn off at the edges as to expose the base metal beneath. Besides, nickelisation does not entirely prevent the oxidisation of steel and iron.