TECHNOLOGICAL CHEMISTRY WITT. 261 



ate this industry with all its ramifications is impossible. Neverthe- 

 less I can not help mentioning the appreciable growth of a branch of 

 this industry which is almost as old as this society. This is the 

 manufacture of chemical products and preparations for photography, 

 whose expansion has been closely connected with the development of 

 scientific photochemistry and with the introduction and populariza- 

 tion of dry photographic plates with their proper processes of de- 

 velopment. 



Not less interesting are the chemical and technical aspects of the 

 perfumes newly created and developed during the last forty years. 

 This field, which is completely developed along its principal lines at 

 the present day, was still unexplored at the time when the German 

 Chemical Society was founded. Its expansion is reflected more com- 

 pletely in the pages of our transactions than anywhere else. Step 

 by step nature has been imitated in its creations, and in this field 

 perhaps more than anywhere else the synthetic chemist has taken 

 paths which follow those of nature. 



xVmong synthetic industries we should count the technology of 

 explosives, although here it is a matter less of constructing molecules 

 than of storing up energy in a form easily liberated. In this indus- 

 try great progress has been recorded, almost all of which depends on 

 the utilization of the facts expressed by the law of Sprengel, ex- 

 pounded about forty j^ears ago, and on the employment more and 

 more of safe explosives which can be detonated only by an initial 

 ignition, in place of bodies themselves exj^losive. The possession of 

 such explosives and the application to the phenomena of explosion 

 of modern methods of observation have alone made possible the new 

 orientation in ballistics, which is well known to all of us. 



If we consider all this technological progress that I have mentioned 

 and much more which I must refrain from describing, we must agree 

 that as far as apj)lications are considered our science has reached a 

 high state of development. But just as scientific research, in spite 

 of the abundance of results, still presses forward, so will technology 

 not stand still, but will continue to attack more and more difficult 

 problems. 



"\Mien this society was founded there was already, it is true, a very 

 well-developed series of chemical industries, but their activities were 

 limited almost entirel}^ to the extraction, purification, and transfor- 

 mation of natural products. An industry operating synthetically 

 on a large scale is a development solely of the last forty years. To- 

 day we are striving for even more lofty ends. We have dared to lay 

 a hard}^ hand even on the great processes of nature in seeking to 

 influence them according to our needs. It is this that we behold in 

 the great factories where many are striving to utilize the nitrogen 

 of the air. Many methods have been proposed to attain this end; 



