SUNLIGHT UPON METHYL ALCOHOL. 71 
decomposition of H.0:—this substance being itself formed by the inter- 
action of water and free atmospheric oxygen—it would seem that the 
phenomena of atmospheric electricity may be traced to the action of plants, 
if the view is correct that the free oxygen of the atmosphere is to be 
attributed to the action of plants.” 
“These experiments possibly raise the question whether some of the 
experiments which have been described on the action of light, in discharg- 
ing negative electrification may not be due to a moisture-film containing 
some H:0. being constantly formed and decomposed.” : 
H. Thiele * found that hydrogen peroxide was formed by the exposure 
of water and ferrous sulphate to the rays of the quartz mercury light, 
andlater “ that water and air gave the Schénbein reaction for hydrogen 
peroxide after one-half hour exposure to the light of the Heraeus quartz 
mercury lamp and also reduced the concentration of hydrogen peroxide 
in water from 3 per cent to 0.0017 per cent in two and one-half hours. 
It seems to be proved that the reaction between water and 
oxygen forming hydrogen peroxide is reversible and that the 
equilibrium' point in light is at very low concentrations of hydro- 
gen peroxide. 
Kernbaum* has found that water is decomposed by the penetrating 
rays of radium with the formation of hydrogen and hydrogen peroxide 
and that the quartz mercury lamp will produce the same result, probably 
according to the reaction * 2H.O—=H.0.+ H.. 
He states that this reaction may account for the sterilization” of 
water by means of the ultra-violet light and also for the presence of 
-hydrogen peroxide in rain and snow which is more marked in the day than 
at night. 
He is not correct in his ideas regarding bacteria, which by the way 
have been advanced by prior writers, for their destruction is not due to 
hydrogen peroxide formed by the ultra-violet light. 
Cernovodeanu and Henri* obtained 0.5 milligram of hydrogen peroxide 
per liter on exposure of distilled water for thirty minutes, at a distance of 
30 centimeters, to the light of a Westinghouse Cooper Hewitt lamp of 220 
volts. 
Courmont, Nogier, and Rochaix* could find no hydrogen peroxide after 
a twenty-minute exposure to the ultra-violet rays. 
Chlopin“ found that moist air exposed to the ultra-violet rays forms 
hydrogen peroxide, ozone, and nitrogen pentoxide. 
* Ber. d. deutschen chem. Ges. (1907), 40, 4914. 
“ Ztschr. f. ang. Chem. (1909), 22, 2472. 
“Compt. rend. Acad. sci. (1909), 148, 705. 
*“Tboid. (1910), 149, 273. 
“H. Thiele and Wolf, Arch. f. Hyg. (1907), 60, 29. Courmont, Nogier 
and Rochaix, Compt. rend. Acad. sci. (1910), 150, 1453. Cernovodeanu and 
Henri, Compt. rend. Acad. sci. (1910), 149, 365 and others. 
“ Compt. rend. Acad. sci. (1910), 150, 52. 
“Tbid., 1433. 
® Ztschr. f. ang. Chem. (1911), 71, 198. 
