Fire Hazard of Oils.
George H. Hurst, F. C. S., of Manchester, England, recently gave an interesting lecture there on oils as illuminants, lubricants, “and for manufacturing purposes.” The lecturer dealt first with the origin of oils, explaining how the fatty oils are obtained from animal and vegetable matters, and the use of such oils for soap making, paint mixing and other purposes. He also showed by means of diagrams the plant used for obtaining the hydrocarbon oils from shale and crude petroleum. The main products from shale and petroleum are said to he naphtha, burning oil, lubricating oil and paraffine wax. It was shown by experiment how to obtain the flash point of oil, the fatty oils having the highest flash point, about 600 degrees Fahr. Fatty oils being natural oils, the flash point it was said could not be altered, but mineral oils can be got at any flash point according to their degree of refinement, 350 degrees Fahr. being considered safe for a machinery lubricant, 470 degrees Fahr. for cylinder oil. The influence of oils in producing the spontaneous combustion of cotton or wood was referred to; this was explained as being due to the property which oils possess of absorbing o_____ygen from the air giving rise to the production of heat. If the absorption is great, the heat may rise sufficiently high to cause the cotton or other fibre to take fire. Those oils which, like linseed, cotton and rape oils, absorb oxygen readily, are the most liable to produce spontaneous combustion ; olive, lard and similar oils are not so liable ; while the hydrocarbon oils, being free from the property of absorbing oxygen, do not produce spontaneous combustion. Oils for woolen manufacturing were referred to, and olive, lard and cloth oils were considered safe, but cotton-seed oil was considered as dangerous for the reasons above named.