106 



Composition of the Atmosphere 



ANALYSES OF AIR COLLECTED ON THE ATLANTIC OCEAN. 



Since numerous writers have found noticeable differences in air col- 

 lected over the sea as compared with that collected on the land, a number 

 of samples for analysis were secured of air taken over the Atlantic Ocean. 

 I am indebted for these samples to Mr. Harold L. Higgins, of the Nutri- 

 tion Laboratory, who most caref ully collected them, together with supple- 

 mentary climatic data, on a sea trip between Montreal and Liverpool in 

 November 1910. The glass sampler used was similar in form to that 

 described by Regnault, 1 and consisted of a cylindrical tube 40 mm. in 

 diameter and 245 mm. long, with a capacity of approximately 200 c. c. 

 To each end of the tube was attached a short piece of glass tubing, which 

 was drawn out in a capillary, so that when the sampler had been filled 

 it could be sealed in the flame of a candle or an alcohol lamp. The 

 samples were always taken on the windward side of the vessel, the sam- 

 pling tubes being filled by aspiration with the mouth for a few minutes. 

 A water-seal was provided by drawing the air first through the sampler, 

 then through a gas-washing bottle containing water and attached by a 

 short piece of rubber tubing, thus preventing all contamination by ex- 

 pired air. After sufficient aspiration the tubes were quickly taken to the 

 stateroom and sealed, labeled, and packed in a specially constructed 

 carrying case. No precautions were taken to dry the air before it entered 

 the sampling tubes. Though the samples were taken in November 1910, 

 the analyses were not made until a year later, i.e., October 6 and 7, 1911. 

 The results are presented in table 64. Aside from the constancy in the 

 oxygen percentages, the most striking feature of the results in this table 

 is the extraordinarily low percentage of carbon dioxide in the samples 

 collected on November 7 and 10. In fact, all of the carbon-dioxide values 

 are lower than normal. 2 



Table 64. Analyses of ocean air collected between Montreal and Liverpool. 



1 Regnault, Annates de Chimie et de Physique, 1852, ser. 3, 36, p. 385. 



2 The injunction of Regnault (Annates de Chimie et de Physique, 1852, ser. 3, 36, p. 

 392) to collect samples of dry air was unfortunately not followed. As the determination 

 of oxygen percentages was the first consideration in this stud}', no especial thought was 

 given in taking the samples to the determinations of the carbon dioxide. 



