Ozone and the Atmosphere. 193 



, — Ozone and the Atmosphere. 



BY ALBERT E. LEEDS, PH.D. 

 Read April 9th, 1878. 



In a paper entitled " Eecent Progress in Sanitary Science,"* 

 1 endeavored to give a short resume of the labors of European 

 physicists upon the estimation of atmospheric oxygen and 

 ozone. I had been unable to find a published analysis of the 

 atmosphere at any locality in the United States, all our knowl- 

 edge upon the composition of the atmosphere being derived 

 from foreign sources. Moreover, few systematic observations 

 upon ozone had been prosecuted, or if carried on, had rarely 

 been published. 



In making the oxygen estimations, Bunsen's methods were 

 in most respects implicitly followed. The eudiometers em- 

 ployed were graduated by ourselves with great care. A gas 

 room was fitted up, in which the thermometric readings rarely 

 varied more than one half a degree during the periods of ob- 

 servation. The flasks employed to collect samples, were of 

 thin glass, 2-§- c. m. in diam., 20 c. m. long, drawn out at one 

 end into a tube about 15 e. m. in length. After cleansing and 

 drying, a pellet of pure potassic hydrate was introduced and the 

 tube sealed at a point about one-third from its extremity. 

 When a sample was taken, the end of this tube was broken off 

 with the aid of a file, the diameter of the tube near the flask 

 narrowed down by heating in a lamp, the air in the interior 

 completely changed by aspiration through a fine tube intro- 

 duced until it nearly reached the bottom of the flask, which 

 was then sealed with the flame. During the summer of 1876, 

 numerous specimens of air were collected at Hoboken and 

 vicinity, at the Centennial Exhibition, Philadelphia, and upon 



* Annals of the Lyceum of Natural History, N. Y., Vol. XI, November, 1876. 



