358 C. A. Young—Catalogue of bright lines 
with a somewhat less degree of probability, zine, erbium and 
re are some coinci- 
No one, of course, can fail to be struck with the number of 
cases in which lines have associated’ with them the symbols of 
two or more elements. The coincidences are too many and too 
close to be all the result of accident, as for instance in the case 
of iron and calcium, or iron and titanium. 
seems rather the most probable, is that the metals operated 
upon by the observer who mapped their spectra, were not abso- 
lutely pure—either the iron contained traces of calcium and 
titanium, or vice versa. this supposition is excluded, then 
we seem to be driven to the conclusion that there is some suc 
similarity between the molecules of the different metals as ren- 
ders them susceptible of certain synchronous periods of vibra- 
tions—a resemblance, as regards the manner in which the mole- 
cules are built up out of the constituent atoms, sufficient to 
establish between them an important physical (and probably 
chemical) relationship. 
ave prefixed to the catalogue a table showing the number 
of lines of each substance, or combination of substances, ob- 
served in the chromosphere spectrum; omitting, however, OXY 
gen, nitrogen ‘and bromine, since with one exception (line 23 
neither of them ever stands alone, or accounts for any lines not 
otherwise explained. 
e instruments and methods of obseryation were the same 
employed in the construction of the Preliminary Casalogy 
Telescope, 9,4; inches aperture—spectroscope automatic, wit 
dispersive force of 12 prisms. : 
e approximate geographical position of Sherman 1s Lon. 
1" 58-2™ west of Washington; Lat. 41°07’; Altitude above se® 
level 8,280 feet; mean height of barometer about 22°1 inches 
Table showing the num incidences between the bright lines observed in the spe 
trum of the pte ys those of the ase oa chemical elements. 
Fe, Ti, Siw) 1 Unknown, ; 52 7 
“ Ba, Scw) Ti, Sew) 3 Fe, 4 | “gg 
Sow Zncw) # 2 Fe 3 | es 
gE tie 11-8 bela 
A w 
: Li, & “ Zn, 1 Mn, 6 - 
Ti, Ba, Siw) L Ca, Cd, 1 Ce, 5 ‘4 
Ba, La, Ecw) L #. Oe, 1 H, + 
tical einai 
