=Manufacture of India-rubber.=[9]--Litharge, massicot, red lead, and sulphide of lead, are generally mixed with rubber. Litharge is regarded not only as a valuable filler for rubber, but has the faculty of hastening vulcanization. All dry-heat goods depend upon it where a dark or black effect is wanted. Every year a few cases are reported in the process of mixing the batches in the weighing room of the rubber factory, or more frequently at the hot calender rolls, where the batch of dry powder containing the lead compound is gradually distributed by hand on to the rubber so as to effect an intimate mixture. The heated air over the rollers causes dust to rise. According to the purpose for which the rubber is wanted, the quantity of litharge in the batch varies. In one factory of fourteen men employed at the calender rolls, ten showed a blue line, five were markedly anæmic, one had weakness of the wrists, and two weakness of grasp[40]. Only one case has been reported since exhaust ventilation was applied locally over each calender roll. In a rubber tyre factory five cases followed one another in quick succession, all in persons employed on the rolls. There should be no hesitation in requiring exhaust ventilation wherever employment in mixing the batches or at the rolls is constant. In general, however, the work in weighing out is intermittent, and reliance is placed on the wearing of a respirator. No attempt has been made to enumerate all the industries and processes in which lead poisoning may arise. The task would become wearisome, as they are so numerous. Nor is it necessary to give details of all that are known, as it is doubtful whether there can be any different in nature or requiring different treatment from the many which have been described. REFERENCES. [1] Special Report on Dangerous or Injurious Processes in the Smelting of Materials containing Lead, and in the Manufacture of Red and Orange Litharge and Flaked Litharge, by E. L. Collis, M.B. Cd. 5152. 1910. Wyman and Sons, Ltd. Price 6d. [2] Annual Report of the Chief Inspector of Factories for 1901, p. 213. [3] _Ibid._, p. 242. [4] _Ibid._ for 1906, p. 272. [5] H. O. HOFMAN: Metallurgy of Lead. 1906. [6] Annual Report of the Chief Inspector of Factories for 1900, p. 438. [7] _Ibid._ for 1910, p. 154. [8] Special Report above, p. 15. [9] LAYET: Quoted by Oliver in Dangerous Trades, p. 288. [10] DIXON MANN: Forensic Medicine and Toxicology, p. 477. [11] SOMMERFELD: Bekämpfung der Bleigefahr, p. 220. [12] SOMMERFELD: Quoted by Silberstein below, p. 257. [13] SILBERSTEIN: Die Krankheiten der Buchdrucker, in Weyl’s Handbuch der Arbeiterkrankheiten, p. 257. Gustav Fischer, Jena, 1908. [14] TATHAM: Decennial Supplement to Sixty-fifth Annual Report of the Registrar-General. Cd. 2619. [15] Third Interim Report of the Departmental Committee on Certain Miscellaneous Dangerous Trades. C. 9073. 1898.