V* PREFACE. 



attained in this way, inasmuch as the reader is placed in the 

 position of being able to form an opinion forthwith regarding 

 the value of the narrative, and to correct errors and omissions, 

 while the labour of subsequent investigators is lightened. While 

 I could scarcely consider it possible to give an absolutely accu- 

 rate representation of the period in question, with its great 

 wealth of discovery, still it has been my aim to furnish a useful 

 contribution towards the history of the chief chemical facts and 

 theories. 



It is almost unnecessary to say that the book has no preten- 

 sions to completeness. I only felt justified in taking notice 

 of those investigations and ideas which have exercised an 

 influence upon the further development of chemistry, whereas 

 I have at most merely referred to other investigations which, 

 in my opinion, will still exert such influence. An objective 

 treatment of the subject appeared to demand that it should 

 be handled in this way. 



I have not hesitated to carry the history of the develop- 

 ment of chemistry down to the present day, although the 

 difficulty of the task has been greatly increased by my doing 

 so. It is certainly in this part in particular that many correc- 

 tions will still be necessary before the end in view is attained. 

 How different the latest phases of our science will appear to 

 subsequent investigators ! And yet the opinion of a contem- 

 porary is not without value also, when it is moderate and free 

 from prejudices or special leanings. This is exactly what I have 



