1894.] Determinations of the Density of \iirogen Gas. 343 



Nitrogen from N 2 by Hot Iron.* 



December 26, 1893 2-29869 1 , r 



' , Qno } Mean, 2-29904 



December 28, 1893 2-29940 J 



Nitrogen from Ammonium Nitrite passed over Hot Iron. 



January 9, 1894 2'29849 1 



IQ TQQA ,oon fMean, 2'298b9 



January 13, 1894 2*29889 J 



With these are to be compared the weights of nitrogen derived 

 from the atmosphere. 



Nitrogen from Air by Hot Iron. 



December 12, 1893 2-31017 -> 



December 14, 1893 2-30986 (H) I 



December 19, 1893 2-31010 (H) > Mean > 2'31003 



December 22, 1893 2-31001 J 



Nitrogen from Air by Ferrous Hydrate. 



January 27, 1894 2-31024 *| 



January 30, ] 894 2-31010 I Mean, 2-31020 



February 1, 1894 2-31028 J 



In the last case a large volume of air was confined for several 

 hours in a glass reservoir with a mixture of slaked lime and ferrous 

 sulphate. The gas was displaced by deoxygenated water, and further 

 purified by passage through a tube packed with a similar mixture. 

 The hot tubes were not used. 



If we bring together the means for atmospheric nitrogen obtained 

 by various methods, the agreement is seen to be good, and may 

 be regarded as inconsistent with the supposition of residual oxygen 

 in quantity sufficient to influence the weights. 



Atmospheric Nitrogen. 



By hot copper, 1892 2-31026 



By hot iron, 1893 2-31003 



By ferrous hydrate, 1894 2*31020 



Two of the results relating to hot iron, those of December 14 and 

 December 19, were obtained from nitrogen, into which hydrogen had 

 been purposely introduced. An electrolytic generator was inserted 

 between the two tubes containing hot iron, as formerly described. 

 The generator worked under its own electromotive force, and the 

 current was measured by a tangent galvanometer. Thus, on Decem- 

 ber 19, the deflection throughout the time of filling was 3, repre- 

 * The If c O was prepared from zinc and very dilute nitric acid. 



