Vickipedia

SPONTANEOUS COMBU’STION is a phenomenon that occasionally manifests itself in mineral and organic substances. The facts connected with the spontaneous ignition of mineral substances are well known to chemists, and some of them have been already described in the articlepyrophorus(q. v.). Ordinary charcoal does not undergo combustion in air under a temperature of 1000°, but in some states it is liable spontaneously to acquire a temperature which may lead to unexpected combustion. Thus, lamp-black impregnated with oils, which contain a large proportion of hydrogen, gradually becomes warm, and inflames spontaneously. According to M. Aubert, Chevallier, and other French observers, recently-made charcoal, in a state of fine division, is liable to be spontaneously ignited without the agency of oil; but we are not aware that this phenomenon has been observed in this country. There have been many instances of the spontaneous ignition of coals containing iron pyrites, (q. v.) when moistened with water. The pyrites which most readily give rise to spontaneous combustion are those in which the protosulphide is associated with the bisulphide of iron; and these occur in the Yorkshire coals from Hull, and in some kinds of South Wales coal. Sulphur has no tendency to spontaneous combustion, but Dr. Taylor refers to an instance that came to his own knowledge, in which there was reason to believe that the vapor of bisulphide of carbon in an india-rubber factory was ignited by solar heat traversing glass. Phosphorus, when in a dry state, has a great tendency to ignite spontaneously, and it has been observed to melt and take fire (when touched) in a room in which the temperature was under 70°. The ordinary lucifer-rnatch composition is luminous in the dark, in warm summer nights, which shows that oxidation, and therefore a process of heating, is going on. Hence, large quantities of these matches kept in contact may produce a heat sufficient for their ignition. ‘ I have seen them ignite,’ says Dr. Taylor, ‘as a result of exposure to the sun’s rays for the purpose of drying.’—Principles and Practice of Medical Jurisprudence, 1865, p. 603.

From these cases occurring in the mineral kingdom, we pass to the consideration of spontaneous combustion in organic substances Passing over the accidents that may result from the admixture of strong nitric or sulphuric acid with wool, straw, or certain essential oils, and which, if they occur, are immediate and obvious, we have to consider the cases in which, ‘ without contact with any energetical chemical compounds, certain substances—such as hay, cotton and woody fibre generally, including tow, flax, hemp, jute, rags, leaves, spent tan, cocoa-nut fibre, straw in manure-heaps, &c.—when stacked in large quantities in a damp state, undergo a process of heating from simple oxidation (eremacausis) or fermentation, and, after a time, may pass into a state of spontaneous combustion.’—Taylor, op. cit. p. 606. There is undoubted evidence that hay and cotton in a damp state will occasionally take fire without any external source of ignition. Cotton impregnated with oil, when collected in large quantity, is especially liable to ignite spontaneously; and the accumulation of cotton-waste, used in wiping lamps and the oiled surfaces of machinery, has more than once given rise to accidents, and led to unfounded charges of incendiarism. Dr. Taylor relates a case in which a fire took place in a shop ‘ by reason of a quantity of oil having been spilled on dry sawdust.’ According to Chevallier, vegetables boiled in oil furnish a residue which is liable to spontaneous ignition; and the same chemist observes that all kinds of woollen articles imbued with oil, and collected in a heap, and hemp, tow, and flax, when similarly treated, may ignite spontaneously.

In the case of Hepburn v. Lordan, which came before Vice-chancellor Wood in January 1865, and was carried by appeal before the Lords Justices, in the following month, an attempt was made to prove that wet jute was liable to undergo spontaneous combustion; and the great fire at London Bridge in 1861 was referred to the spontaneous combustion of jute in its ordinary state. With regard to the latter hypothesis, Dr. Taylor remarks that it is wholly incredible, and from experiments which he made for the defendants in the above lawsuit, and on other grounds, he holds that there is no evidence of moist jute undergoing spontaneous combustion; but, he adds, although no cases are recorded, it is probable that jute, cocoa-nut fibre, and linen and cotton rags, imbued with oil, might undergo this change. Dry wood is supposed by Chevallier and some other chemists to have the property of igniting spontaneously. Deal which has been dried by contact or contiguity with flues or pipes conveying hot water or steam at 212°, is supposed to be in a condition for bursting into flame when

air gets access to it; and the destruction of the Houses of Parliament, and many other great fires, have been ascribed to this cause; but from the experiments of Dr. Taylor (op. cit., p. 615) this view must be regarded as untenable.

It is still an open question whether such organic nitrogenous matters as damp grain or seeds of any kind ever undergo spontaneous combustion. In a case recorded in the Annales d’Hygiène for 1841. MM. Chevallier, Ollivier, and Devergie drew the conclusion that a barn had caught fire from the spontaneous combustion of damp oats which were stored in it. No such cases are known to have occurred in this country.

The subject of the article is of extreme importance, not only because it may cause great destruction of life and property, but because it may lead to unjust charges of incendiarism.—For further details regarding it, the reader is referred to Graham’s ‘ Report on the Cause of the Fire in the Amazon,’ in the Quarterly Journal of the Chemical /Society, vol. v. p. 34; to the article ‘Combustion’ in Watts’s Dictionary of Chemistry, vol. i.; and to the elaborate chapter on this subject in Taylor’s Principles and Practice of Medical Jurisprudence.