414 Antozone and Peroxide of Hydrogen. 



peroxide of hydrogen towards the galvanic current (1879), that 

 in the electrolysis of water no hydrogen peroxide is formed. 



Will the same be found to be true of Schonbein's statement, 

 that in the oxidation of phosphorus exposed to moist air, along 

 with ozone, a by no means inconsiderable quantity of peroxide 

 of hydrogen is formed ? This point was investigated by the 

 author in the course of a research into the by-products obtained 

 in the ozonation of air by phosphorus, with the result of confirm- 

 ing Schoubein's observation. The amount of hydrogen peroxide 

 was determined by analysis of the water employed in washing 

 the ozonized gas, the iodine liberated by the washed gas being 

 attributed entirely to the decomposition effected in a neutral 

 solution of potassium iodide by the ozone. The proportion of 

 hydrogen peroxide to the ozone, as determined by this method, 

 was only one to four hundred. But later, the author has re- 

 investigated the subject, estimating not only the hydrogen perox- 

 ide held back in solution, but the entire amount present in the 

 ozonized gas, and has found that its proportion to that of the 

 ozone may exceed one to three. The two substances, as Schone 

 has pointed out, may be present in the same vessel in quite a 

 concentrated form for a long interval, without effecting a com- 

 plete mutual decomposition, and when highly dilute, may co- 

 exist for hours. 



One question of very great interest still remains : — is Peroxide 

 of Hydrogen present in the atmosphere? As yet, except as an 

 inference from other meteoric phenomena, there is no evidence 

 that it is. Meissner (18G3), Schonbein (1868), Struve and 

 Schmid (1869), and Goppelsroder (1871), believed that they 

 had succeeded in demonstrating the presence of peroxide of hy- 

 drogen in rain. Houzeau, whose authority in matters of chemical 

 climatology no one would feel disposed to question, — seeing that 

 lie gave a lifetime of arduous study to their elucidation, — made 

 very numerous analyses of the atmospheric precipitates, at dif- 

 ferent seasons of the year, occurring in the vicinity of Rouen 

 (1868). But he did not succeed in finding peroxide of hydrogen 

 either in snow or rain-water, nor in natural or artificial clew. 



But in the year 1874, Scheme made an elaborate investigation 

 of the subject, and obtained results which established, that in 

 that locality at least, and at the time his experiments were per- 



