202 Prof. Schoenbein on some Properties of Ozone. 



must be taken for M + HO. This view of the nature of cya- 

 nogen offers, in my opinion, the advantage of assigning a 

 similar constitution to two bodies, being, as to their chemical 

 bearings, so very hke each other, whilst the established theory 

 is forced, in spite of that similarity, to consider one of those 

 bodies as an elementary substance, and the other as a com- 

 pound consisting of principles which differ from chlorine as 

 much as night from day. 



If we compare the compounds which oxygen forms with 

 elementary bodies with the compounds which chlorine pro- 

 duces with the same substances, we cannot but be struck by 

 the similarity existing between both series as regards the 

 ratio in which the equivalents of their constituent parts are 

 united. If we except the bromides, iodides, and, to a certain 

 extent, the sulphurets, there are, to my knowledge, no other 

 sets of compounds that bear, with respect to the relation al- 

 luded to, so close an analogy to each other as the oxides and 

 chlorides do. That similarity loses, however, its peculiar cha- 

 racter so soon as we admit the correctness of the old views. 

 According to them, it is, as it were, a matter of course that 

 chlorine unites, for instance, with iron in the same definite 

 proportions as oxygen combines with that metal ; for CI being 

 M + O, protochloride of iron is =M + FeO, and the perch lo- 

 ride SM + FegOg. 



S^ It is a very remarkable exception to that rule according to 

 which no elementary substance forms a real chemical com- 

 pound with water, that chlorine and bromine produce hy- 

 drates. If we take chlorine and bromine for compound sub- 

 stances, their capability ol' chemically uniting with water loses 

 its exceptional character and comes under the general rule. 



Admitting with Berthollet that chlorine is muriatic acid 

 united to oxygen, and considering ozone as a compound ana- 

 logous to chlorine, we are obliged to parallel water to mu- 

 riatic acid, and admit that with regard to oxygen, water acts 

 the same part as muriatic acid does. Water uniting so inti- 

 mately with the stronger bases that these compounds cannot 

 be decomposed by any degree of heat, and the same substance 

 combining so readily with many other basic oxides, water may 

 be considered as a sort of acid ; and that view has very often 

 been taken of the chemical nature of the compound mentioned. 

 We may therefore be allowed to consider water as an acid and 

 arrange it beside muriatic acid. As to ozone, it appears not un- 

 likely that it is an isomeric modification of peroxide of hydro- 

 gen, i. e. composed of one equivalent of water and one equiva- 

 lent of oxygen. Now chlorine being considered as a compound 

 consisting of one equivalent of muriatic acid and one equivalent 



