System of Chemistry, by Prof. Berzelius. tS' 



nomena of combustion, or, in other words, of fire. Agreeably to this 

 classification, susceptibility of union with oxygen and combustibility 

 are confounded ; to which I object, because oxidizement frequently 

 ensues without combustion, and combustion occurs often without ox- 

 idizement. 



Speaking of chlorine, (Treatise, p. 276, vol. I.) it is alleged that 

 it supports the combustion of a great number of bodies, of which a 

 majority ignite in it at ordinary temperatures. If oxidizement be 

 identical with combustion, how can this word be employed with pro- 

 priety in the case thus quoted, where oxygen is not present? If com- 

 bustion in the case of chlorine is applied only to those instances in 

 which reaction with other bodies is attended by the phenomena of 

 fire, why is not the term equally restricted in its application in the 

 case of oxygen ? 



Oxygen differs so far from the substances usually called combusti- 

 bles, that they will produce fire with oxygen, and with but few, if any 

 other substances; while oxygen will produce fire with many substan- 

 ces. But this characteristic of producing fire with many substances, 

 applies to chlorine, and as chlorine does not produce fire with oxy- 

 gen, it is devoid of the only characteristic which should entitle it to 

 be treated as a combustible, if combustibility and susceptibility of un- 

 ion with oxygen be identical. 



Hence, if it be deemed proper in the case of oxygen to place the 

 bodies with which it enters into combustion in one class, designated 

 as combustibles, while oxygen is distinguished as the common " com- 

 huranf^ of them all, there is equal reson for placing chlorine in a like 

 predicament. The impropriety of designating the substances com- 

 prised in his halogene and amphigene classes, with the exception of 

 oxygen as combustibles, upon the basis of their susceptibility of ox- 

 idizement, must be evident from the fact, that fluorine is not oxid- 

 izeable, while it is so perfectly analogous to the others, especially 

 chlorine, in its properties, that it would be disadvantageous to class it 

 apart. 



Berzelius objects to the use of the word " comburant,''^ (equiva- 

 lent to the English word supporter) upon the ground that the same 

 substance may alternately be a supporter and a combustible. I should, 

 however, go farther, and likewise object to the use of both words, as 

 tending to convey the erroneous impression, that in combustion, one 

 of the ponderable agents concerned, performs a part more active than 

 the other ; whereas, in all such cases, the reaction must evidently be 



Vol. XXVU.— No. 1. 10 



