A. W. Wright on the Action of Ozone, ete. 29 
discharge was of the silent kind, but on admitting oxygen it 
immediately took the form of direct sparks. 
The quantity of the solution used ih these experiments was 
much greater than would be needed in order to exhibit the 
characteristic reactions of ozone to an audience of moderate size. 
Art. VIL—On the Action of Ozone upon Vulcanized Caoutchouc ; 
by Prof’ ArTHUR W. WRIGHT. 
_ IN using the Holtz’s electro-machine, in the summer season, 
it is often very difficult to make it retain any considerable 
charge, or even to keep up its action for more than a 
minutes. The ebonite insulators are found to have lost in a 
e degree their insulating power, and to have become con- 
the warmer portion of the year unused. The surface of the 
ebonite becomes hygroscopic, condensing upon itself a large 
amount of moisture, the accumulated liquid being sometimes 
So abundant as to trickle down in drops. 
aving noticed on one occasion that this liquid had an acid 
I was led to examine it more closely, and the ordinary 
tests very speedily showed it to be sulphuric acid. Its pres- 
ence was a sufficient explanation of the defective insulation. 
Similar deposits of moisture were found upon the ebonite 
ty of two induction coils some time after they had been 
As nothing containing sulphur had been used about the 
apparatus, the acid was ovidasie derived from the ebonite 
self The first thought was that the material had been heated 
in the process of vulcanization sufficiently to oxidize the sul- 
hur; but as the sulphurous oxide, if thus formed, would be 
