372 Literature of Ozone. 



also that contained in the contraction-volume, or, in all, three 

 volumes of ordinary oxygen. The density of ozone, therefore, 

 was to the density of oxygen, as three to two, or 1.6584; the 

 density of ordinary oxygen being 1.105G. 



Soret inferred rather than demonstrated these relations, inas- 

 much as in his first set of five experiments, the ratio of the total 

 volume of ozonized oxygen absorbed by the turpentine, to the 

 contraction-volume, was 2.4, and in his second set of seven 

 experiments, 1.81; both of these results being far from 2, the 

 theoretical number. 



However, in 1872, Sir Benjamin Brodie, by the introduction 

 of methods of exact, volumetric character, supplied a rigorous 

 experimental demonstration. He obtained in a set of eight 

 concordant experiments made with oil of turpentine, for the 

 ratio between the whole diminution in the volume of the origi- 

 nal oxygen, to the diminution in volume of the ozonized 

 oxygen, as a mean result, 3.02 to 2.02. Operating in the 

 same manner with a neutral or slightly alkaline solution of 

 sodium hyposulphite, he obtained as a mean result of 27 con- 

 cordant experiments, the ratio 3.02 to 2.02. In these experi- 

 ments, the actual weight of the oxygen absorbed, could not be 

 determined otherwise than by calculation from the alterations 

 in volume. But by the oxidation of stannous chloride, under 

 proper conditions, he effected a direct determination, and found 

 that the weight of the oxygen absorbed from the ozonized oxygen 

 by the stannous chloride, was almost exactly three times the 

 weight absorbed from the same gas by potassium iodide. At 

 the same time the volume in the first case was almost exactly 

 twice the contraction-volume, as determined by the latter re- 

 agent. 



