ATMOSPHERIC DUST IN THE ARCTIC 

 REGIONS. 



BY PROFESSOR WILLIAM H. BREWER. 



The atmosphere always con- 

 tains dust, and the phenomena 

 relating to it have long been a 

 subject of much interest to me. 

 It is obvious that the air of the 

 Arctic regions must be much less 

 dust-laden than our own ; there- 

 fore, during our trip to Greenland 

 I made such observations on the 

 related phenomena as were prac- 

 ticable without the use of special 

 instruments. 



The dust (including smoke) in 

 the atmosphere is generally spoken of as an impurity or 

 pollution. It renders the air less transparent, and is the source 

 of various diseases and ailments of both mankind and animals. 

 In this sense it is an impurity. It may also be so considered 

 in the sense that it is not gas, but consists of solid particles 

 suspended in a gaseous medium. In another sense it is not 

 an impurity, but rather a permanent constituent of the 

 atmosphere, always and everywhere present. It is also not 

 an impurity in the sense that as a constituent of the air it 

 plays an essential part in many meteorological phenomena. 

 It varies enormously in its quantity, its fineness, its origin, its 

 chemical composition, and in its efEects, but is never entirely 

 absent. 



