j_|g The Lines of Discovery in the [March, 
the adtion of air upon moist phosphorus, no other sources 
of ozone of pradtical utility have been discovered. 
The fadt that Schonbein so stoutly insisted on, and event- 
ually so triumphantly established, the identity of the ozone 
from whatever source derived, must not be lost sight of in any 
estimate of his merits as a discoverer. The earliest attack 
came from De la Rive, who attributed the odour to metallic 
oxides set free from the metals used as electrodes, or as 
terminals in eledtric discharges. But Schonbein pointed 
out that besides the improbability of an odour arising from 
solid bodies, this hypothesis required that solid bodies 
should have the property of indefinite suspension in the 
atmosphere instead of being deposited or washed down by 
water (1840 to 1843). , A A 
The next attacks came from Fischer, who regarded 
Schonbein’s ozone as probably peroxide of hydrogen, and 
from Williamson, who thought there were two kinds of 
ozone, — one the ozone given off in electrolysis, and which 
he regarded as a higher oxide of hydrogen, differing from 
the previously well-known peroxide, and the other formed 
by the aftion of phosphorus on moist air. But Schonbein 
disposed of both objedtions : the first, by showing that the 
chemical and physical properties of ozone are not the pro- 
perties of peroxide of hydrogen ; the second, by demon- 
strating that whatever might be the true nature of ozone, 
the gaseous matter obtained in the eledtrolysis of water was 
in all respeCts identical with that formed by the adtion upon 
air of moist phosphorus (1844 to 1845). 
During these first five years Schonbein was busily engaged 
in ascertaining the properties of ozone. Since no peculiar 
methods were employed in the furtherance of these, disco- 
veries, they need not detain us here further than briefly to 
summarise them, and to point out what correftions have 
been rendered necessary by the labours of subsequent in- 
vestigators. They are— 1st. Its eminent oxidising powers, 
as shown by its ability to transform most metals into their 
higher oxides, and to raise the lower oxides into the condi- 
tion of peroxides. Certain of the non-metals— phosphorus, 
chlorine, bromine, and iodine— are similarly oxidised. 
Schonbein’s statement that it does not unite with nitrogen 
under ordinary circumstances, but enters into combination 
when alkali is present, has been abundantly disproved— 
among others, by Berthelot (1878), who has shown that no 
combination occurs even when alkali is present. It oxidises 
sulphites and nitrites into sulphates and nitrates, and many 
sulphides into their corresponding sulphates. It destroys 
