Rensselaer Union, Volume 9, Number 7, Rensselaer, Jasper County, 2 November 1876 — Spontaneous Combustion of Charcoal. [ARTICLE]

Spontaneous Combustion of Charcoal.

-Thelate Mr. Braidvvood,superintendent of the London Fire Brigade, England, remarks that lampblack and charcoal, when the smallest quanflfyof oil gains access to them, are morfe'ihflammable than sawdust anfi the vegetable and animal textiles, and should pot be 'Admitted among ships’ The kinds of wood generally used for the manufacture of charcoal for gunpowder are the black dogwood, the willow and the aider. 1 Thesd varieties are-all well adapted for the purpose, though for the best brands of sporting powder the dogwoOd is sftki to be ’preferable. Tbe wool 4s converted into charcoal by heating it in iron cylinders. After the charcoal is removed from these vessels, it is placed in iron coolers provided with tightly fitting Kds, and-allowed to stand for some hoars until quite booh It is then sent to tbe mill to be ground, and is afterwards mixed with the other ingredients for gunpowder. With reference now to this process, Prof. F. Hargreaves vouches that there are urauy instances recorded where the charcoal has taken fire the second day after grinding. With tlie process of this occur, rence we are by this time quite familiar. The same observer, it appears, is algo aware of tfie fact that the pulverization of the charcoal is not absolutely indispensable for such ignition to ensue, for he adds, at the conclusion of his remarks: “The absorption (namely, of oxygen) with sticks of charcoal is nofso quick sis with ground charcoal, aqd .hence the spontaneous cbmbustion rtf stick charcoal does not ocour so often.” Mr. Hatfield, in a paper containing “ Observations bn the Circumstances producing Ignition in Charcoal at Atmospheric Tempera--tores,” in- ti>« PhilotopJuarl Magazine , sm%“s the following; “If fwtnty o*; thirty hfladfed of cimrcoal, itea of ifihfm#divhiiofi, -be put together in a heap, and left undisturbed, spontane. bits cbflibtistirtp' generally occurs.” Hfl records, in veHticatiofi' of this statement, Mq that covered about ten Jcet i square and four feet deep.' In tliree days the temper, ature kid int reasedfo ninety degrees Fab., altlaiigli & was al lirsc oifiy fifty-seven degrees, that of the surrounding air. Oft to 100 degrees; and on the seventh combustion had commenced in several places ” Dr. C. T. Jackson, in a communication of what hfts just preceded: “Three times,” lie remarks, *‘ I have set fire to

charcoal -ht'-tempOraWrefr below that of paring, while at Bangor, Me., Tor a rets-t-u%, in'which 1 had occasion to show an artificial volcano. I .took a trav filled with gunp»wde‘r andlaid it on the stqvfc to dty>.; J theft, took•» paper of pulverized .charcoal,.such as is sold by apothecaries for tooth powder, the charcoal being wrapped in whitepaper, and placed it Op top of the gunpowder that was being 1 dried upon thetopof the stove. Having occasion to go out, I toofeofi the paper c# charcoal and laid it-an the table.. When frhme hack, in abbnt twenty minutes, I smoking. The charcoal wafc completely consumed. During all this time the gunpowder remained on the stove tinekpladed. y | vTt^^‘ this.: _Vyhde ii w ork in my laboratory, r had o&Asum. to use a piece of charcoal for blow-pipe experiments. Itv»ebldO«vn into my cellar and brought up a piece of light, fine, round charcoal'suited for that purpose. It was damp. I laid it upon the top of a column stove to diy, directly beside a tin pan containing water, which was not boiling and never did boil there. 1 took the charcoal off the stove and laid it on the table. A short time afterward, 1 discov-* ered thatit was -on fire all through its muss. I laid ft aside and it burned entire! v toashh*. . . . I repeatedtheexperiinent again intentionally, watching it carefully, aari.<vfth the same result. " exnianation of the cases first quoted is not difficult to find. The charcoal possesses.

wonderful porosity and great power for occluding gaffes. This absortlve quality ia supplemented by a specie* of selective power: in virtue of which, it absorbs oxygen with much more avidity and in much greater quantity than nitrogen. The enormous condensation which gas suffers by absorption into the pores of the charcoal is attended with the liberation of a quantity of sensible heat that is the equivalent of the work the atoms have accomplished; while simultaneously, the eminent non-conducting property of tbe charcoal hastens the period of active combustion by preventing the dissipation of the heat thus evolved, and concentrating it upon the porous mass.— lie view. p- .: ; • ' ■ •• •