52 HISTORY OF CHEMISTRY. [LECTURE IV. 



series. He wished, in fact, to establish a regularity in chemical 

 compounds, such as had been assumed in the distances of the 

 planets from the sun, and, in order to accomplish this, he had 

 probably corrected many of his results. 



Another department of Richter's " stochiometric investiga- 

 tions " must be mentioned here ; that is, his work upon metallic 

 precipitations. He determines the quantities of the metals as 

 they mutually precipitate one another from their solutions, and 

 employs the numbers obtained to ascertain the proportions of 

 oxygen in the oxides. Here again, his way of expressing him- 

 self leaves much to be desired. He says : 12 



" When an aqueous solution of a metallic neutral salt is so 

 decomposed by an inflammable metallic substrate, that is, by 

 another metal in the metallic state, that not only does the 

 metal which was dissolved separate out in a wholly metallic 

 state, but also that neither the dissolving acid solvent nor the 

 water associated with it, is decomposed, then the masses of the 

 vital air which must unite with equal masses of the metallic 

 substrates, in order to make their solution in acids possible, are 

 inversely proportional to the masses (or weights) of the separat- 

 ing and of the separated metallic substrates from the metallic 

 neutral salts." And at another place: 13 "The quantitative 

 order of the specific neutrality of the metals towards vitriolic 

 acid does not by any means follow the usual order in which 

 one metal is separated -by another from the solution in the 

 acid ; on the contrary, it is wholly analogous to the inverse 

 quantitative order of the removal of the inflammable matter 

 and of the respective combination with vital air." 



It is worthy of mention that Richter introduced the name 

 Stochiometry, which signifies the measurement of the pro- 

 portions in which substances combine. 



Fischer, on the other hand, deserves credit for having 

 combined Richter's various tables into a single one. In this 

 connection, he expresses himself as follows : 14 " It is only 



12 Neuere Gegenstande. 3, 83. 13 Ibid. 3, 127. 14 Berthollet, 

 Statique Chimique. German translation with explanatory comments by 

 Fischer, I, 135. 



