208 ANNUAL OP SCIENTIFIC DISCOVERT. 



plidrus, in burning', change? the oxygen, with which it combinos, 

 ironi the gaseous to the solid Ibi-m, thus increasing the quantity 

 of heat gt'nt'ratcd ; while sulphur, in hiUMiing, is chaniiid from 

 the solid to the gaseous state, tiuis absorl)iiig heat, ami diniinish- 

 ing tiie quantity produced by the combustion. 



These tiieoretieal views have i)een conlirmed by careful experi- 

 ment. The results olitaini-d by Andrews from liis elal)orato 

 invfstigations were, that 1 pound of phospliorus in l)in-iiiiig to 

 phosphoric acid generates sullicient heat to raise the temperature 

 of 5,747 pounds of water 1° C. ; while 1 i)ound of sulphur, in 

 binning, raises the temperature of only 2,2l'0 i)oiuids of water 1°. 



Ibil it is not the qnanlity of heat that is to Ite considered in this 

 case, but tiie intensity ; which is in proportion to the quantity 

 contained in a cultic inch or other given volume. This, however, 

 oidy increases the dilliculty, for (lu! piioi)hoius llame being con- 

 densed to a solid, while tiiat ()f sulphur is dilliised as a gas, the 

 intensity of heat ouglit to be still more in favor of the phosphorus 

 than the quantity. 



The usual explanation given for the failure of wood to ignite in 

 a plios[)liorus llame is, that tiie surface of liie wood is instantly 

 covered by a film of phosjihoric acid, which protects it from com- 

 bustion. As we have no belter explanation to ofl'er, we raise no 

 objections to this. 



Th(! products of combustion, then, in the burning of a match, 

 are, first, pli()s]jhoric acid from the Ijurning of the phosphorus; 

 then sulphurous acid, from the burning of the sulphur; and, 

 linally, carbonic acid and water from the burning of tiie wood. 



This is far from being an exhaustive examination of the sub- 

 ject. Tli(^ hydrogen and carbon of the wood do not combine 

 directly with the oxygen of the air, but the wood first undcu-goes 

 destructive distillation, with the production of several hydrocar- 

 bon gases, which rise in the air and i)roduce the llame l)y their 

 combustion ; and, after the wood is burned, the ash that is left 

 behind is made ui> of some sixteen elements, combined with oxy- 

 gen in various j)roportions. The activity of the burning, also, is 

 increased 1j\- adding to the paste some suijstanee containing 

 oxygen which is held by feeble allinity, and which is, therefore, 

 readily given up to the sulphur, phosphorus, and wood. Among 

 the substances emi)loyed for this (dlice are saltpetre and the per- 

 oxides of lead and manganese. In a complete examination of 

 the reactions of the combustion, the decompositions of these oxi- 

 dizing agents, M'ith the resulting compounds or elements, would 

 demand consideration. All that might be said in relation to the 

 burning of a friction match would fill a large volume, — Scientific 

 Amencan. 



OXIDATION OF VEGETABLE OILS. 



In a memoir upon this subject, read to the Academy of Sciences 

 of Paris, M. Cloez announces the following results of his experi- 

 ments and observations : — 



1. That all the fat oils absorb oxygen from the air, and increase 

 in weight by quantities which ditier, for different kinds of oil 



