NITROGEN'. LORD RAYLEIGH. 



boron is also its true atomic weight. See Comptes Rendus, 

 T. 116, p. 695; 1893. 



<f The application of my general method of calculation 

 gives us a true appreciation of the excellency of the labora- 

 tory work made by Mr. Henry Gautier; besides, we were 

 right in our confidence in the great value of the crystallized 

 carbides of Mr. Moissan for the direct determination of 

 atomic weight by means of carbon. 



" Mr. Gautier has also made several determinations on the 

 sulphide, chloride and bromide of boron. By the method 

 of the means and the use of German values of the auxiliary 

 elements, he obtains as many values for the atomic weight 

 of boron, and finally adopts the number 11.016 (1. c. p. 681). 



"By applying our general method to the experimental 

 data of Mr. Gautier, we find the mean 11.004, which 

 indicates that the true value must be 1 1 exactly. 



lt In addition, the laboratory work of Mr. Gautier, in this 

 our direct reduction and without any hypothesis, demon- 

 strates that the German data used in the calculations of 

 Mr. Gautier present several errors. We shall return to this 

 subject." 



This is my full communication as printed in the Comptes 

 Rendus, of the meeting of the Academy, held on June 18, 

 1900. 



The report of the Section of Chemistry often referred 

 to, was made at the meeting of December 27, 1900, fully 

 half a year later. 



This gives the essential data under consideration as they 

 are on record in this official organ of the Academy of 

 Sciences, of Paris, the Comptes Rendus. 



III. THE ATOMIC WEIGHT OF NITROGEN. LORD RAYLEIGH. 



The name at the head of this chapter is not that of a 

 chemist, in the common acceptance of that term. The Right 

 Honorable Lord Rayleigh is Professor of Natural Philoso- 

 phy of the Royal Institution of Great Britain , London. 



But Lord Rayleigh has produced the experimental deter- 

 minations which enable us to establish the true value of the 



