OXYGEN. 185 



PART IL PONDERABLE BODIES. 



Introductory Remark. 



I SHALL here repeat what was stated in the Introduction, p. 18, 

 that a real element is an undecomposable body ; that, in relation to 

 our knowledge, an element is merely an undecomposed body. 



Our evidence on this subject being only negative, it follows that 

 any body and all bodies, now admitted as elementary, may hereafter 

 be decomposed. 



Should we, for argument's sake, admit the improbable result, that 

 all compound bodies may be hereafter reduced to two, the smallest 

 number of principles with which it is possible to form a third body, 

 we should even then not be certain, that these two were real ele- 

 ments ; for they might be decomposed into two, three, or four others, 

 and they again into five, six, seven, or eight others, and so on ; pro- 

 ceeding from the greatest apparent simplicity, to the greatest com- 

 plexness. 



It is proper to recal to the recollection of the student, that the an- 

 cient hypothetical elements, earth, air, fire and water, have all been 

 proved to be compound, and that there are now more than fifty* un- 

 decomposed bodies, among which are three supporters of combustion, 

 oxygen, chlorine and iodine ; about forty metals, and seven combusti- 

 bles, that are not metallic, namely, phosphorus, carbon, hydrogen, sul- 

 phur, nitrogen, boron and selenium. Nitrogen, as already observed, 

 is thrown into this class, as resembling them very much in its relations 

 and character, although it is not in the popular sense a combustible. 



INORGANIC BODIES. 

 SIMPLE SUPPORTERS OF COMBUSTION. 



SEC. I. OXYGEN. 



1. NAME, Oxygen^ derived from ogus and ysivopat or /svvaw, signi- 

 fying, therefore, the generator of acids ; a name imposed by the 

 framers of the new nomenclature ; the former names were, dephlo- 



* Dr. Turner's 2d edition, gives fifty two, including bromine and selenium. 



t Several authors, (as Thenard, 5th Ed. Vol. I, p. 166,) consider the name oxygen 

 as improper, because it is not the sole acidifier ; but it is the great ruling acidifier, it 

 being the sole agent in almost all cases, and therefore the name is proper. We 

 might as well reject the name chlorine, because it is not the only greenish yellow 

 body. 



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