34-8 HISTORY OF CHEMISTRY. [LECTURE XVI. 



Although such unexpected discoveries were thus made, 

 still they will not exercise any considerable influence upon 

 chemistry as a whole, since all these "elements" apparently 

 resemble argon, and probably do not enter into many com- 

 pounds. Hence it may be said that these interesting investiga- 

 tions will probably not prove of great significance, as regards 

 their consequences, and that in this respect they will fall short 

 of other researches which have not excited the interest of such 

 wide circles. 



I merely recall here the isolation of fluorine by Moissan in 

 i886, 78 and the discovery of nickel carbonyl and analogous 

 compounds by Mond in 1890, and pass on to consider more 

 particularly the investigation of the chemistry of nitrogen, 

 which has made great advances in recent years. 



The discovery of hydroxylamine, by Lessen, falls under 

 review here, although, of course, it took place at a much earlier 

 date (in i865). 79 It has not been referred to previously, how- 

 ever, since its importance only came to be recognised gradually, 

 a result to which Victor Meyer's researches on the oximes 80 

 and their stereo-isomerism 81 materially contributed. 



The preparation of phenylhydrazine, by Emil Fischer, 82 also 

 deserves mention here. It must be looked upon as of par- 

 ticular importance, on account of its leading to the clearing 

 up of the sugar group. 83 Following upon this there are the 

 valuable researches of Curtius, who discovered hydrazine in 

 iSSg, 84 and hydrazoic acid in iSgo. 85 The utilisation of these 

 two substances has already led to numerous investigations, and 

 will lead to others. As worthy of mention, I also refer to the 



78 Comptes Rendus. 103, 202 and 256. 79 Zeitschrift fur Chemie. 8, 

 551 ; Annalen, Supplementband 6, 220 ; 160, 242 ; 161, 347 ; etc. 

 80 Meyer and Janny, Berichte. 15, 1324; Janny, Ibid. 15, 2778; 16, 

 170; Meyer, Ibid. 16, 822; Petraczek, Ibid. 16, 823; etc. 81 H. 

 Goldschmidt, Berichte. 16, 2176 ; Auwers and Meyer, Ibid. 21, 784, 3510 ; 

 22, 537 ; etc. ^ Berichte. 8, 589 ; compare also Strecker and Roemer, 

 Ibid. 4, 784 ; and Zeitschrift fiir Chemie, 14, 481. 8:>> Berichte. 17, 579. 

 84 Curtius and Jay, J. pr. Chem. [2] 39, 27. * r > Curtius, Berichte. 23, 



