50G ON THE SPECTRA OF FLAMf:S RESULTING FROM BESSEMER PROCESSES. 
Lines of potassium and the edges of manganese bands are shown to have been 
intensified l^y the proximity of iron lines in some cases. The following are examples : 
X 5864, Fe X 5870, Mn band 5269, Fe X 5268'9. The line X 5361 is common to both 
potassium and manganese, and 5343 to potassium and iron. A similar case has 
already been observed by us with two rubidium lines, 4216’3 and 4203’2, and two 
iron lines. 
(4.) A. New Line of Potassium with Variable Intensity. 
The new line in the spectrum of })otassium, wave-length aj)proximately 4642, 
varies in intensity or disap 2 )ears altogether; but jjrovided the temperature is 
sufficiently high to cause tlie element to emit this ray, its brilliancy or intensity of 
cliemical action is increased by diminisliing the quantity of vajjour in the flame, and 
so giving greater freedom of motion to the molecules. From a minute examination of 
all the jilates on which the line 4642 has been photograq)hed, and of those in which it 
is absent, and also having regard to the conditions under wliich the spectra in each 
case were produced, we conclude that it is not so much reduction of temperature, as 
reduction of the quantity of vapour in the flame, which increases its intensity. 
This much is quite certain, that increase of intensity does not in this instance indi¬ 
cate a higher temjierature. 
We desire to record our sincere thanks for 2 )ermission and facilities given to us to 
visit the works for the jDuiqDose of carrying out these researches, first to Mr. Arthre 
C ooRER, Managing Director of the North-Eastern Steel Company, and to Mr. F. W. 
Webb, Chief Engineer of the Locomotive Dej)artment of the London and North- 
Western Railway; for assistance cordially rendered by Mr. C. H. Ridsdale, the 
chemist to the North-Eastern Steel Conqjany, and by our friend Mr. E V. Clark, 
A.R.S.M., sometime Demonstrator of Chemistry and Assaying in the Royal College 
of Science, Dublin. 
We have also gratefully to acknowledge that the exi^enses iq) to the end of 1895 
were defrayed out of a sum voted upon the recommendation of the Government Grant 
Clommittee of the Royal Society. 
