108 Mineral Constituents of Dust and Soot from various Sources. 



Wave-lengths of other Lines than Iron in Spectra from various kinds 

 of Dust and Soot, and in Meteorites. 



r> 



lines. 



Sodium. 



5896-11 Mean 

 5890 -2 J 5893-0 

 3303-1 1 Mean 

 3302-5 J 3302-3 



Potassium. 

 5805-0 



4047-41 Mean 

 4044 -0 J 4045 •? 



Lithium. 



4602-3 

 3232 -7 



Ccesium. 

 4557 -0 



Rubidium. 



4215 -7 

 4202 -4 



Thallium. 



5349 -6 

 3775-6 



Gallium. 



4172-2 

 4033 -0 



Indium. 



4511 -0 

 4102 '0 



Calcium. 

 4226-9 Aline. 



Calcium Oxide. 



A strong 

 band. 



A band. 



5598 -0 



to 

 5435 -0 

 6253 -0 



to 

 6116-0 



6075-01 , i 



. , , I A weaker 

 to a bout ^i-i 



5985-0 J W - 



Magnesium Oxide. 



3929-01 A band, 



to > strong, 

 3856 -0 J diffuse. 

 3834-01 A band, 

 to about > strong, 

 3805-0 J diffuse. 



Strontium. 

 4607-0 



Lead. 



4057 -6 

 3682 -9 

 3639 -2 



4289 

 4274 

 4254 

 3605 

 3593 

 3578 



4034 

 4033 

 4031- 



3273 -6 

 3247-0 



3383 

 3282 



3618 -5 

 3609 -8 

 3571-2 

 3461 -0 

 3433 -0 



Chromium. 

 A triplet, 



A triplet. 



Manganese. 



Lines which, often ap- 

 pear like one broad 

 line. 



Copper. 



Silver 



NicheL 



Tbe bines observed are 

 near tbe positions of 

 such as are here indi- 

 cated, and are prob- 

 ably identical with 

 them. There is also a 

 line 3525, the only one 

 observed in Cleveland 

 pig iron. It does not 

 appear in these ana- 

 lvses. 



Some of the lines were measured with a micrometer and the wave-lengths deduced 

 from a curve on an enlarged scale drawn from Rowland's measurements of iron 

 lines in the solar spectrum. 



with other dust and soot, and we cannot be certain whether it conies 

 from only one source or not, but soot, as a rule, can be separated 

 by washing it away from the heavier matter. The occurrence of nickel 

 in soot and flue dust was certainly unexpected. It is probably 

 disseminated in extremely minute traces in coal, and its concentration 

 in soot is owing to the conditions in a coal fire being favourable 

 to the formation of nickel tetra-carbonyl and its subsequent de- 

 composition 



