204 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



goes to prove that the oxygen emitted by plants does not con- 

 tain an appreciable proportion of ozone. 4Z>, 1873, VI., 303. 



ACTION OF OZONE ON BENZOLE. 



The action of ozone upon benzole has recently been investi- 

 gated by Houzeau and Thenard, who have obtained some in- 

 teresting results. A variety of acid products, chiefly formic 

 and acetic acids, are formed, and also a peculiar body, which 

 the authors name ozobenzin. This body, dried in vacuo, is a 

 solid, white, anhydrous substance, and extraordinarily ex- 

 plosive. Either by a blow or by heat it detonates violently, 

 the explosion of only a few decigrammes of the substance 

 producing such a disturbance of the surrounding air as to 

 shake the windows of the room. In fact, it is extremely dan- 

 gerous to handle, not more than three to. five milligrammes 

 being safe to keep on hand at one time. Its chemical con- 

 stitution is yet to be made out. Ann. Chem. and Pharm. 



A NEW EXPERIMENT IN OZONE. 



In a recent lecture, Dr. Andrews communicated a new ex- 

 periment in relation to the formation of ozone, by which it 

 was seen that coarsely pounded glass shaken in a vessel con- 

 taining electrolytic oxygen (or oxygen that has become par- 

 tially converted into ozone by the passage of the electric 

 spark) rapidly destroys the reactions of the ozone. This ex- 

 periment forms a new link between a purely mechanical ac- 

 tion and a chemical change, closer than any hitherto observed. 

 12^1, IX., 175. 



METAMERISM IN INORGANIC CHEMISTRY. 



When, as frequently happens among organic compounds, 

 two different substances have exactly the same ultimate 

 composition in parts per cent, of the same elements, they are 

 called in general isomeric. When, however, the difference 

 between them is demonstrably structural that is, when they 

 contain the same elementary atoms, only differently arranged 

 the expression metameric is used. Cases of metamerism 

 are common in organic chemistry, but until very lately not 

 an instance of it had been discovered in the inorganic world. 

 At the late meeting of the National Academy of Sciences in 

 Washington, Professor Wolcott Gibbs, of Harvard Univer- 



