LECTURE XVI. 



THE DOCTRINE OF PHASES VAN DER WAALS'S EQUATION THEORY OF 

 SOLUTION ELECTROLYTIC DISSOCIATION ELECTRO-CHEMISTRY 

 ATTAINMENT OF HIGH TEMPERATURES Low TEMPERATURES 

 THE NEW ELEMENTS IN THE ATMOSPHERE THE CHEMISTRY OF 

 NITROGEN TRANSITION TEMPERATURE STEREO -CHEMISTRY 

 RACEMISM SYNTHESES IN THE SUGAR AND URIC ACID GROUPS 

 IODOSO-COM POUNDS TERPENES AND PERFUMES NEW NOMEN- 

 CLATURE. 



WHEN we look back upon the development of chemistry during 

 the last fifteen or twenty years, we find that it is distinguished 

 by the constantly increasing prominence of physical or, as 

 many call it, general chemistry, which from small beginnings 

 has advanced to the position of a science of the first rank. 

 Contributions to this end have, naturally, been made in particular 

 by eminent scientists such as Horstmann, Gibbs, van der Waals, 

 and van 't Hoff, who have devoted themselves to this department 

 exclusively and, by their ideas and discoveries, have brought 

 about its advancement. On the other hand, however, it can- 

 not be denied that this advancement does not coincide for- 

 tuitously with the appearance of Ostwald's great Text-book of 

 General Chemistry, but that the latter, in which the attempt is 

 for the first time successfully made to give a complete repre- 

 sentation of what has been accomplished up to the present in 

 this department, aroused and stimulated the tendency towards 

 investigation in an altogether exceptional manner. Further, 

 the establishment by Ostwald and van 't Hoff of the Zeitschrift 

 fur Physikalische Chemie, in which all the more important 

 investigators in this department are active as collaborators, 

 has done a great deal to advance the subject;- so that this 

 publication must be placed side by side with the best journals 



