284 A. LIVERSIDGE. 



cobalt) found in dusts, such as have been described in 

 this paper, is of meteoric or cosmic origin; the particles 

 resemble those obtained from meteorites and do not look 

 like pieces abraded from manufactured articles, further 

 they are not usually rusted to any great extent, whereas 

 small particles of ordinary iron and steel (even if small 

 amounts of cobalt and nickel are present) usually rust 

 quickly; the difficulty is to prevent them passing wholly 

 into the form of oxide, then too, the minute spheres of iron 

 found in what are regarded as meteoric dusts and deposits 

 are not found in flue dusts nor in volcanic dusts; as already 

 pointed out, they have, however, been formed artificially 

 by Professor Schuster from meteorites. 



The following shows however, that a telluric form of 

 spherulitic iron does occur : — In the Trans, of the Royal 

 Society of Canada for 1890, Dr. G. 0. Hoffmann describes 

 an occurrence of metallic iron containing nickel and cobalt 

 on St. Joseph Island, Lake Huron, Ontario. The iron 

 occurs as minute spherules in a thin coating of limonite on 

 the fissure faces of surface specimens of quartzite, the 

 spherules amounting to 60°/° of the coating by weight. The 

 largest spherules are about *3 mm. in diameter. Sp. gr. 

 6*86. The part of the spherules soluble in hydrochloric 

 acid contained : — 



Iron 



... 97-79 



Sulphur 



•13 



Magnesia ... 



•57 



Phosphorus 



... 1-07 



Nickel 



•11 









Cobalt 



•23 





ioo-oo 



Copper 



•10 







The portion insoluble in hydrochloric acid (nonmetallic) 

 9'76°/o was made up of spherical and ovoid grains and con- 

 sisted mainly of silica. The spherules were made up of a 

 siliceous nucleus, coated with a humus like substance which 

 in turn was covered with the metallic layer; the author 



