170 
PROFESSOR W, N. HARTLEY ON 
detected by the groups of lines lying between 39297 and 3749'4, also between 
3745'4 and 3G83. Chromium is recognized by its two sets of triplets. A more 
particular examination of nickel and cobalt has not yet been made with a view of 
ascertaining their most persistent lines. 
The prominent manganese lines were detected in the spectra obtained from 
malleable cobalt and nickel, also in fine steel. 
Descriptions of Spectra and Measurements of Lines and Bands, with their 
approximate Wave-lengths. 
The Oxy-Coal-Gas Flame. 
The flame was non-luminous. Photographs were taken with a somewhat wide slit, 
and the exposure wms one hour. The edges of the bands are as sharp as they are 
generally seen in the spectrum of a Bunsen flame, and the lines of which the bands 
are composed are somewhat wide. No attempt was made to purify the coal-gas, as 
the object of examining this spectrum was to determine the origin of any lines which 
might be caused by hydrocarbons in the oxy-hydrogen flame. Lecoq he Bois- 
BAUDRAX has carefully described variations in the spectrum seen under different 
circumstances in the flame of a Bunsen burner, but there is no occasion to refer to 
these further. [Spectres Lumineux.) 
All the principal bands observed are probabl}? due partly to carbon and partly to 
what is generally considered as the cyanogen sj^ectrura. They are indicated by (C) 
carbon, and (GN)^ cyanogen. The measurements of lines and bands made by other 
authors are indicated thus: —K. and B., Kayser and Bunge; L., Lecoq de Bois- 
BAUDRAN ; L. and D., Liveing and Dewar; D., Deslandees ; W., Watts; F., 
Fjevez. The lines and bands were all measured twice and their wave-leno'ths 
o 
ascertained on two separate occasions. /S, y, S, e are groups or bands described by 
Lecoq de Boisbaudran. 
