CHAPTER XVII 



MOLECULAR ARCHITECTURE 



A. THE RISE OF ORGANIC CHEMISTRY 



The development of inorganic chemistry, 1766-1816. 



It can scarcely fail to be noticed that almost the whole of 

 the work described in the sixteen preceding chapters falls 

 within a very narrow period of time. Occasionally it has 

 been necessary to go back to study the origins of things, or 

 forward to study their more mature developments ; but by 

 far the greater part of the experiments that are described 

 were carried out during the latter part of the eighteenth and 

 the early years of the nineteenth century. 



This narrow period, undoubtedly the most fertile in 

 the history of chemistry, begins with Black's work on 

 " Magnesia Alba," published in 1755. If this investigation 

 be set aside as merely a herald of the dawn, it will be found 

 that almost every chapter is filled with accounts of experi- 

 ments made in the fifty years from 1766 to 1816. The 

 former date saw the publication of Cavendish's papers 

 " On Factitious Air," and was followed almost immediately 

 by the wonderful development of Pneumatic Chemistry 

 which we owe to the successful labours of Priestley. The 

 latter date saw the completion of Gay-Lussac's work on the 



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