KEY AND INDEX VOLUME 



A KEY TO THE TEXT 



THE present volume is devoted to Indexes which 

 analyze the text of the preceding volumes from various 

 standpoints. 



Two of these indexes are of somewhat novel char- 

 acter, inasmuch as they introduce specific explanatory 

 matter concerning technicalities of science, or biograph- 

 ical data regarding important scientific workers, in 

 addition to guiding the reader to the pages of the pre- 

 ceding volumes. 



The third Index is of more conventional character, 

 and is designed solely as an analysis of the text; yet 

 its references are always so phrased as to convey a 

 clear idea of the exact subject to which the reader is 

 guided. 



AN ANALYSIS OF THE TEXT 



As preliminary to these Indexes it will, perhaps, oe 

 a convenience to the reader to have presented here a 

 very brief analysis of the varied contents of the pre- 

 ceding volumes from two different standpoints: First, 

 a very general survey of the subjects treated; secondly, 

 a more detailed presentation of these subjects as re- 

 vealed by the titles of the successive chapters, volume 

 by volume. 



Perhaps the most general analysis that could be 

 made of the text as a whole would characterize it as a 

 comprehensive presentation of the growth of scientific 



