[ 26? ] 



XLV. On Cinis; a Khid of Alkaltne Earth formed during 

 the luGhierailon of IVood, not yet noticed by Chemists in 

 their Nomenclature. Addressed to George Pearson, 

 M.D. F.R.S. &c. ^^ Samuel L. MixciiiLL, M. D, 

 Meinber of Congress y ts'c. in a Letter, diUed Nciv York, 

 September ^0, 1803, and covimnvicated to ISlr. Tilloch 

 at the particnlar recjncst if the Author. 



JL HE phsenomeua of combustion have by no means been 

 examined to their full extent. The decomposition of wood 

 by fire is a very complicated process. There is much more 

 to be remarked in it ihan has been noticed in books. Ja 

 particular the formation of a new kind oH alkaline earth ren- 

 ders it remarkably interesting. In New York, where wood 

 is the principal fuel of the inhabitants, and where great 

 quantities of potash are manufactured from the fixed mass 

 which remains after burning, I have availed myself of the 

 opportunities aflbrded to find out some of the details. Those 

 I have endeavoured to exurcss in the following record of 

 facts : 



When a quantity of wood (in a solid, not a rotten state^ 

 oak or hickory for example, has received anticrouon (the 

 repelling principle or calorie) enough to render it capable 

 of decompounding the gaseous oxide of light (oxygenous 

 air), it begins itself to lose its vegetable structure and to 

 assume new forms. The anticrouon first dilates the wood 

 by increasing the repulsion among its particles; then it re- 

 pels the water which it contained to such a degree as to 

 convert it into steam or aqueous gas. The moisture being 

 thus exhaled, and the wood left shrunk, perfectly dry, and 

 highly heated, its carbon attracts a portion of oxygen from 

 the gaseous oxide of light with which it is closely mvested. 

 The immediate consequence of this is, that a portion of 

 detached light becomes visible, and a quantity of extricated 

 anticrouon spreads through and over the wood, and extends 

 about the surrounding spaces. In proportion to the amount 

 and rapidity of the oxygen, abstracted from tlie gaseous 

 oxide of light, will the extricati;d light be vivid, and the 

 stparated heat be intense. While the liberated anticrouon 

 and light, just nascent from their latent condition, arc 



quaintcd is thut by Dizc, in Ro^ur's Ojrivnr. siir la Phvsiqnf, for the 

 year lyyo. But tlierc srems to be great iiason to dcubr tliL-ir being cor- 

 rect, because the auih>>r makes all the coitii to conslsr of copper and tin, 

 without iayinj; a word ot the Ua<i found yi the Greek coins, or the zhic 

 found in the Romiii^. 



thus 



