Spontaneous Combustion.

Spontaneous Combustion.

A lecture on this subject was delivered before the Leeds Chemists’ Association, a few days ago, by Mr. T. Fairley, F. R. S. E. The lecturer showed that the term spontaneous combustion may be used either in a general or special sense. In the one it refers to all fires not due to the actual contact of hot bodies or the direct action of heat. In the other it is restricted to the combustion produced by the chemical action of bodies originally cold upon each other. He explained and showed experimentally numerous cases of spontaneous combustion due to the latter cause, more especially where the combustible bodies are finely divided so as to expose a large surface to the action of the air or other gases acting upon them. Finely divided metals, such as lead, iron, zinc, take fire when exposed to the air. Recently fires have occurred on board ship due to the action of sea water on cargoes of zinc-dust. The lecturer alsot nstanced the class of nitro-compounds, of which nitro-glycerine and gun-cotton are the best known. These, if impure, become still more liable to spontaneous cornbustion and explosion, as shown by the numerous accideiUs which have occurred. He referred to the Australian emigrant ship believed to have been lost by the explosion of badly prepared gun-cotton, forming part of its cargo. Of fires due to other causes, he mentioned the numerous instances of buildings, trees, etc., set on fire by the electric discharge, and in particular the recent fire at Inverary Castle ; also the fires caused by the heating of the bearings of machinery by friction or any kind of resistance to motion. Mr. Fairley next described the conditions under which ordinary materials—such as wet hay, sawdust, oily waste, etc.—tend to heat and fire spontaneously, illustrating these by experiments with readily inflammable substances. He described the mode of conducting experiments to ascertain the heating tendency of oils used in manufactures. In experiments undertaken for this purpose he found that cotton-seed oil and similar drying oils applied to cotton wool and kept in a warm atmosphere took fire spontaneously in eight hours, or even a shorter time, Other causes of fire different from the preced ing are those by dangerous substances, either on ccount of their low ignition point, or because they cannot be extinguished by water, or because they give off an inflammable vapor at temperatures near the ordinary range of our climate. Sulphide of carbon is a material which is now extensively used for extracting fat from seeds, wool waste, etc., and for other purposes. It is also present sometimes in considerable quantities in ordinary coal gas. It is very inflammable, taking fire at a temperature not far above that of boiling water—300 deg. Fahr. While ordinary combustibles can be readily extinguished by the application of water, petroleum and similar light oils which float on water cannot be extinguished by this means; in such cases sand, ashes, dry earth, etc., are the proper materials to throw on a fire. The act of Parliament relating to petroleum requires that such liquids shall not be sold without a special label, where they give an inflammable vapor at temperatures below too deg. Fahr., and the lecturer showed how the “ flashing test ’’ can be applied to distinguish such liquids. In conclusion, he drew attention to the application of tungstate of soda to render muslin and other fabrics non-inflammable. The thanks of the meeting were presented to Mr. Fairley for his able lecture on the motion of Mr. Richard Reynolds, seconded by Mr. Pocklington.— Post Magazine.

A lecture on this subject was delivered before the Leeds Chemists’ Association, a few days ago, by Mr. T. Fairley, F. R. S. E. The lecturer showed that the term spontaneous combustion may be used either in a general or special sense. In the one it refers to all fires not due to the actual contact of hot bodies or the direct action of heat. In the other it is restricted to the combustion produced by the chemical action of bodies originally cold upon each other. He explained and showed experimentally numerous cases of spontaneous combustion due to the latter cause, more especially where the combustible bodies are finely divided so as to expose a large surface to the action of the air or other gases acting upon them. Finely divided metals, such as lead, iron, zinc, take fire when exposed to the air. Recently fires have occurred on board ship due to the action of sea water on cargoes of zinc-dust. The lecturer alsot nstanced the class of nitro-compounds, of which nitro-glycerine and gun-cotton are the best known. These, if impure, become still more liable to spontaneous cornbustion and explosion, as shown by the numerous accideiUs which have occurred. He referred to the Australian emigrant ship believed to have been lost by the explosion of badly prepared gun-cotton, forming part of its cargo. Of fires due to other causes, he mentioned the numerous instances of buildings, trees, etc., set on fire by the electric discharge, and in particular the recent fire at Inverary Castle ; also the fires caused by the heating of the bearings of machinery by friction or any kind of resistance to motion. Mr. Fairley next described the conditions under which ordinary materials—such as wet hay, sawdust, oily waste, etc.—tend to heat and fire spontaneously, illustrating these by experiments with readily inflammable substances. He described the mode of conducting experiments to ascertain the heating tendency of oils used in manufactures. In experiments undertaken for this purpose he found that cotton-seed oil and similar drying oils applied to cotton wool and kept in a warm atmosphere took fire spontaneously in eight hours, or even a shorter time, Other causes of fire different from the preced ing are those by dangerous substances, either on ccount of their low ignition point, or because they cannot be extinguished by water, or because they give off an inflammable vapor at temperatures near the ordinary range of our climate. Sulphide of carbon is a material which is now extensively used for extracting fat from seeds, wool waste, etc., and for other purposes. It is also present sometimes in considerable quantities in ordinary coal gas. It is very inflammable, taking fire at a temperature not far above that of boiling water—300 deg. Fahr. While ordinary combustibles can be readily extinguished by the application of water, petroleum and similar light oils which float on water cannot be extinguished by this means; in such cases sand, ashes, dry earth, etc., are the proper materials to throw on a fire. The act of Parliament relating to petroleum requires that such liquids shall not be sold without a special label, where they give an inflammable vapor at temperatures below too deg. Fahr., and the lecturer showed how the “ flashing test ’’ can be applied to distinguish such liquids. In conclusion, he drew attention to the application of tungstate of soda to render muslin and other fabrics non-inflammable. The thanks of the meeting were presented to Mr. Fairley for his able lecture on the motion of Mr. Richard Reynolds, seconded by Mr. Pocklington.— Post Magazine.