G -Flame Spectra at High Temperatures. [June 1, 



screw of the micrometer was cut with 100 threads to the inch, and 

 the magnifying power generally used was 10 diameters. 



Characters and Extent of the Spectra observed. Just as in- the 

 ordinary use of the spectroscope we must be prepared to see the lines 

 of sodium, and in hydrocarbon flames the bands of carbon, so in these 

 spectra the sodium lines and the strongest lines belonging to the 

 emission spectrum of water vapour are also always present. 



In addition, the kyanite yields tbe red line of lithium, which is no 

 inconvenience but a positive advantage, serving, as ifc does, to indicate 

 where the spectra commence. 



A large majority of the metals and their compounds all terminate 

 somewhere about the strongest series of water vapour lines. Typical 

 non-metallic spectra are sulphur, selenium, and tellurium ; the first 

 yields a continuous spectrum with a series of beautiful fluted bands, 

 the second a series of fine bands, occurring at closer intervals, and 

 the third is characterised by bands still closer together and near the 

 more refrangible termination of which four lines occurring in 

 Hartley and Adeney's spark spectrum of tellurium are visible. In- 

 crease in atomic mass causes shorter periods of recurrence of bands. 

 In line spectra it is the reverse ; increase in atomic mass causes 

 greater periods in the recurrence of lines. Charcoal and carbon mon- 

 oxide yield chiefly continuous spectra ; the latter, however, exhibits 

 some carbon lines. The hydrocarbons yield the well-known spectrum 

 of carbon bands with also those attributed to cyanogen. Of metallic 

 elements, nickel, chromium, and cobalt yield purely line spectra ; 

 antimony, bismuth, silver, tin, lead, and gold beautiful banded 

 spectra (spectra of the 1st order) accompanied by some few lines. 

 These spectra are finer than those of selenium and tellurium. 



Iron and copper exhibit lines, and, less prominently, bands. 

 Manganese has a beautiful series of bands and a group of three very 

 closely adjacent lines. Aluminium gives a fine continuous spectrum 

 with three lines, origin uncertain, zinc a continuous spectrum with- 

 out lines, and cadmium a spectrum consisting of one single line only, 

 X 3260-2. 



Of compounds, chromic trioxide yields a continuous spectrum with 

 six lines belonging to the metal, copper oxide a fine band spectrum 

 with two lines of the metal, magnesium sulphate gives a spectrum 

 of magnesium oxide consisting of broad degraded bands composed of 

 closely adjacent fine lines and one line belonging to the metal, X 2852. 



The sulphates of calcium, strontium, and barium give both bands 

 of the oxides and lines of the elements. Phosphorus pentoxide 

 yields a continuous spectrum with one peculiar line, seen also in the 

 spectrum of arsenic. 



The chlorides of the alkalis give also lines of the elements with a 

 more or less continuous spectrum, which, it is believed, is due to 



