230 ANNUAL EECORD OF SCIENCE AND INDUSTRY. 



mine being removed and colorless fluorcscin produced. If 

 now water be added and a few drops of potassium perman- 

 ganate solution, the fluorescin changes to fluorescein, and the 

 liquid becomes quite green and almost opaque in reflected 

 light. 35 C, VIII., January, 1875. 



PEROXIDE OF HYDROGEN IX THE ATMOSPHERE. 



Schone has made a series of experiments in the vicinity 

 of Moscow to determine the amount of hydrogen peroxide 

 in the atmosphere. Between the 1st of July and the 1st of 

 December, 1874, he examined for this purpose one hundred 

 and thirty specimens of rain and twenty-nine specimens of 

 snow. Of the whole number of specimens of rain, only four 

 failed to respond to the test, though out of the twenty-nine 

 specimens of snow twelve gave no reaction. Having estab- 

 lished the fact, the author continued his investigations with 

 reference to the following points: (l) Form of occurrence 

 of hydrogen peroxide in the atmosphere whether gaseous 

 or dissolved in the fluid or solid rain or hail ; (2) relation to 

 other meteoric phenomena, to time of day, and to season of 

 the year; (3) relation to the ozone of the atmosphere; (4) 

 how produced in the air; (5) part played by it geologically 

 and botanically ; (6) action upon the animal economy when 

 breathed ; and (7) hygienic importance. For this purpose, 

 all the rain, hail, snow, dew, and frost were collected and 

 tested for hydrogen peroxide, the analyses being quantita- 

 tive when possible. Further, at various times, especially in 

 clear weather, artificial dew and frost were prepared and 

 examined. Careful meteorological records were kept dur- 

 ing the entire interval at the adjoining observatory. The 

 ozone was determined with a Schonbein's ozonometer. The 

 results show that the quantity of hydrogen peroxide iu rain 

 varies from 0.04 to 1 milligramme per liter ; that the 

 larger the drops the greater the amount; that the first rain 

 after dry weather is poorer in peroxide than that which falls 

 later; that the peroxide is greatest when the wind is south 

 and southwest, that in the rain brought by the equatorial 

 current being greater than that which falls in the rain pro- 

 duced by the conflict of this with the polar current, or 

 brought by the latter current itself; that the relative quan- 

 tity of peroxide in rain increases from the summer solstice 





