HISTORICAL INTRODUCTION. 7 



did not perceive the existence of the principle 

 which Wenzel had investigated. Yet the analy- 

 ses of Bergman and of other chemists, though 

 less accurate, and inconsistent with the fact 

 which had led Wenzel to his investigation, were 

 adopted by chemists in general, and thus their 

 attention was withdrawn from one of the most 

 important steps which the science has ever made, 

 and the great improvement itself was delayed 

 for more than thirty years. 



II. In the year 1792, Richter, who during The same 

 the latter part of his life had the superrnten- supported 

 dence of the porcelain manufactory at Berlin, byli 

 published a work entitled, Anfangsgrllnde der 

 Stocky ometrie, oder Messkunst Chymischer Ele- 

 mente, Elements of Stochyometry, or the Mathe- 

 matics of the Chemical Elements. This work con- 

 sists of four thin volumes, which were printed at 

 Breslau, during the years 1792, 3, and 4. It 

 was followed by a periodical work, entitled, 

 Ueber die Neuern Gegenstdnde der Chymie, on 

 the New Objects of Chemistry. This work was be- 

 gun in 1792,* and continued in twelve different 

 numbers, or volumes, till the year 1807, the 

 period of Richter's death. For he died on the 

 4th of May of that year.t In these works, he 



* In my copy, the date of the first part is 1799, but it is a second edi- 

 tion. The second part was printed at Breslau in 1793. Hence I infer, 

 that the first part appeared in 1792. 



f Gehlen's Jour, (second series) IV. 127. 



A 4 



