METEORIC DUSTS, N.S.W. 281 



various specimens examined. Minute quantities of gold 

 were met with in two of the dusts examined, viz., from 

 Gundagai and the University tank, that from the University 

 beams also yielded a metal resembling platinum, some of 

 the other dusts have yet to be tested. These metals were 

 especially sought for when grinding and washing the dusts 

 in an agate mortar to separate out the particles of metallic 

 iron, as this is a much more delicate test for minute 

 quantities of gold and platinum in such materials than any 

 chemical test; they were obtained in the form of minute 

 spangles. 



The dust from the University beams, collected in 1882 

 from a portion of the roof some distance from the Chemical 

 Laboratory and completely cut off from it by several divid- 

 ing walls and the ceilings, yielded a minute spangle of a 

 white malleable metal insoluble in nitric acid even after 

 evaporating the acid down to dryness, hence it appears to 

 be one of the platinum metals. The particle was too minute 

 to admit of applying other wet tests, hence it was not 

 treated with aqua regia. 



A dust from Muswellbrook (N.S.W.) yielded particles 

 of a non-magnetic grey metal readily soluble in acid, this 

 was probably zinc or zinc and lead from a galvanized iron 

 roof. Hartley and Ramage found lead in several meteorites, 

 in volcanic and other dusts, as well as in chimney soots 

 (Proc. Roy. Soc. 1901). 



The mud from the University tank, which may have been 

 collecting for 30 years, as the tank had probably never 

 been cleaned out since it was put up, yielded spangles of a 

 yellow malleable metal, insoluble in nitric acid even on 

 evaporation, and therefore presumably gold, the metallic 

 particles although visible without a microscope were very 

 small and insufficient for the application of other tests; 

 there were also present particles of a yellow metal resem- 



