1895.] On the new Gas obtained from Uraninite. 113 



The law enunciated above may also be stated in the following 

 form. 



The increment of each unit of chemical change due to a rise of 

 temperature varies as the increment of each unit of absolute tempe- 

 rature. 



This law is expressed by the formula 



D*/ = mDT/T. 



Chemical Equilibrium. 



A case of equilibrium between the reactions 

 H 2 2 +2HI = 2H 2 + P, 

 2H 2 + P =H 2 



leads to a discussion of the general equations of chemical equilibrium 

 which is given in an appendix to the paper. These equations are 

 employed to interpret the results of experiments published by Dr. 

 Gladstone in the Transactions of the Royal Society (' Phil. Trans., ' 

 vol. 145). They had been previously applied to the case of chemical 

 equilibrium investigated by Professor Dixon in a paper published in 

 vol. 175 of the Transactions of the Royal Society, the reactions in 

 that case being 



H 2 O + CO = H 2 + C0 2 , 



The following Papers were also read : 



I. " On the new Gas obtained from Uraninite. Second Note." 

 By J. NORMAN LOCKYER, C.B., F.R.S. Received May 8, 

 1895. 



Since my communication on the gas obtained from uraninite 

 (broggerite) was sent into the Society, on the 25th ultimo, I have 

 been employing the method I there referred to in several directions, 

 among them to determine whether the spectrum of the gas indicates 

 a simple or a complex origin. 



I was led to make this special inquiry on account of the difference 

 in the frequency of the appearance of D 3 and the other lines to which 

 I referred in the previous communication in the solar chromosphere. 

 For instance, if we take the lines D 3 , 4471, and 4302, the frequencies 

 are as follows, according to Young* : 



* See ' Solar Physics,' Lockyer, p. 612. 



K 2 



