fid-l Prof", Schcenbef n bri sofne Pfvperties of OzoUe} 



iofh^iJeledtrdi^^triical system, as established by Berzeliu^,^ 

 places oxygen at the head of what are called the electro-ne- 

 gative elements, and puts chlorine in a positive relation to that 

 bddtiJ^ It is however a well-known fact, that in a great nunii' 

 hfepoP cases, chlorine, with respect to its electro-negative acti- 

 vity, very much surpasses oxygen. Chlorine is capable of 

 expelling oxygen from a great number of oxides ; chlorine 

 eliminates bromine and iodine from the bromides and iodides, 

 whilst pure oxygen seems not to act upon those compounds. 

 In spite of these exalted electro-negative powers possessed 

 by chlorine, it is apt to produce with oxygen a series of acids' 

 in which chlorine is said to act the part of an electro-positive! 

 principle. I ask, how is it possible that in some cases chlorine 

 proves to be a more electro-negative body, and in another in- 

 stance a more positive one than oxygen ? It seems to me that 

 the facts alluded to are very little in accordance with the prin?" 

 ciples of the electro-chemical system; nay, that they imply a 

 direct contradiction to them, provided chlorine be taken for 

 a simple substance. But if we consider it as oxymuriatic 

 acid, all the anomalies spoken of disappear, and we can easily 

 account for the reactions produced by chlorine. The oxygen 

 disengaged, for instance, during the reaction of chlorine upon 

 potash, comes from the oxygenized muriatic acid, and not 

 from the potash ; and the decomposition of the former is 

 effected by the strong affinity which potash has for muriatic 

 acid. Those who maintain that there is some truth in the 

 principles of the electro-chemical system, must, I think, be 

 inclined to readopt the views of Berthollet, in order to save 

 their endangered theory. ' ' 



Before concluding, 1 shall take the liberty to add some ge- 

 neral considerations regarding the subject I have treated of. 

 By regarding chlorine as an elementary substance, one of the 

 greatest theoretical changes that ever took place in the history 

 of chemistry was effected. Indeed, by Davy's theory, oxygen 

 lost, if I may say so, its royal dignity amongst the elements; 

 and at any rate a very powerful rival was set up in chlorine. 

 Oxygen was no more the body exclusively enjoying the 

 privilege of being the generator of acids, the supporter of 

 combustion, &c. ; that privilege was also claimed for the up- 

 start. But if there should be found good reasons for giving 

 up Davy's hypothesis and readopting the old doctrine, we 

 could hardly help restoring oxygen to its ancient dignities, ' 

 and considering it again as an agent that has not its equal 

 amongst the rest of the elementary bodies. To speak without 

 metaphor, oxygen would become again one of the centres o^f^ 

 chemistry, as it formerly was, and as most likely hydrogeiV^ 



