Rensselaer Union, Volume 9, Number 29, Rensselaer, Jasper County, 5 April 1877 — Spontaneous Combustion. [ARTICLE]

Spontaneous Combustion.

. The following from the New York /Spectator should possess considerable interest for such persons as have no knowledge of the science of chemistry, and who do not understand that all material substance* contain a »tore of latent or undeveloped heat: Doubtless there are many instances of spontaneous combustion on record which are yet unsolved, and which never will, be solved to the satisfaction of all concerned. We do not pretend to explain these mysteries, but simply to draw attention to a mistake we think often made by those who imagine that a high temperature or a vast amount of heat is essential to produce spontaneous combustion. We are apt to forget that there is such a thing as latent heat,;discovered by Dr. Black, and described as “ that portion of the matter of heat which makes no sensible addition to the temperature of the bodies in which it exists.” This latent or undeveloped heat; unlike any other known substance, lies hidden in everything around us; it is stored up till we want it, when the supply is forthcoming. Itmfiy seem strange to those who have not thought much about it when we say on good authority that there is heat in everything,' even ih ice; Of course the amount of latent heat in different substances is not always,the same. One or two familiar illustrations will prove what We assert. Mix suiphuric acid and water, both cold, in certain proportiops; pour cold water on cold lime, and in both cases you have intense heat. We make nitrate of iron ,by combining nitric acid, Water and i?oii, all cold, find in a few seconds the mixtnre wilLboil and continue to boil in the open air for twenty or thirty minutes. A-blacksmith beats or compresses the particles of iron by his hammer, bringing out the latent heat, and the iron is red not. Now, where does all this heat come from if it was not in the acid, water, lime and irqn; before they came in contact with otheg .substances the heat was hidden, or not perceptible to our senses, but was brought out, when required.

Many things have their chemical constitution entirely changed by combination, and in this change evolve a large amount of heat’ Dr. Ure says: “Combustion is the disengagement of heat and light which accompanies chemical combination.” . Prof. Seeley says: “The temperature of ignition varies greatly for the different combustibles. The combustible nature of iron, lead, copper, silver, and gold was not even suspected until a recent qate. Heat always accompanies the union of oxygen with another substance. In slow burning (oxidation) (he hetit is simply diluted in time or space.” Three times Dr. Jackson affirms that he has set fire to temperatures below that of boiling water. “ I once laid a piece of fine round charcoal, but damp, on the top of a column stove to dry, directly beside a tin pKu eotitaining water, which was not boiling, and never did boil there; I took the charcoal off the stove and laid it on the table; a short time afterward I found that it was on fire all through the piece; I put it aside and it burnt entirely -to ashes..’’ Charcoal, it is well known, will ignite if slacked in large heaps. A remarkable case of spontaneous combustion occurred at Leamington, England, in May, 1842. A hair m attress was supposed to be on Are- ‘‘ It turned outon examination, that there was only a thin covering of hair, the interior of. the mattress being made up, among other things, of roughlybroken flax and oakum, quittances only requiring the contact of oil and grease to Ignite by themselves, but which would be ignited more quickly by such an elevation of temperature as mere animal heat.” Mr. Badderly, in his report of “ The Fires in London,” for 1858, repons yet another remarkable case at the residence of Mr. Fletcher, in Manchester, who, on entering his room one afternoon, found his sofa on Are. Having dragged it into the yard and put out the fire that was burning in the interior, he found the sofa had been filled with cap. bottoms and woolen materials,,, which, being somewhat greasy, had at this low temperature itrnited. We are told that the temperature of almost any room is high enough to fire phosphorus spontaneously if it is in a finely-powdered condition. After the great fire in the custom-house stores in Dublin, irf 1883, a witness testified “ that on the floor where the fire was first seen there were stored tallow, sumac, cork, wood, furniture, palm oil, cotton, wool, junk and hemp;” all these were placed side by side, without any regard to their combustibility. “The wool was near the oil, and fifteen casks of tallow were near the cottan,” and yet the author(iea , wondered why there waa. a fire. Stores there must be, latent heat there always will be, education of the right kind there should be, in order that those most concerned may understand the nature ot the materials handled, and not conclude that a fire is impossible because there to, in their estimation, no grqat amount of sensible heat.