relating to Chemical Mass, 



245 



Table V. 



.r. 



y, calculated. 



y, found. 



1 



84 



867 



2 



74-4 



760 



3 



67-2 



684 



4 



61 2 



621 



5 



55-8 



563 



6 



50-9 



50-8 



7 



46-4 



460 



8 



424 



41-7 



9 



387 



380 



10 



35 3 



347 



11 



322 



321 



VIII. Ferric Citrate and Potassic Ferrocyanide (loc. cit. p. 199, 

 pi. 9. fig. 5). — One equivalent of ferric citrate was mixed with 3 

 &c. equivalents of potassic ferrocyanide in presence of hydric 

 oxalate, and the increasing blue coloration determined. Unit 

 of x = 3 equivalents. The equation is 



y=103 (-2010)* + 23 (-7699)*. 





Table VI. 





X. 



y, calculated. 



y, found. 



1 



30-6 



296 



2 



14-2 



144 



3 



9-1 



96 



4 



66 



6-4 



5 



5-0 



40 



IX. The above equations represent the greater part of Glad- 

 stone's results as figured at the end of his memoir. I have not 

 worked out the remainder, either (1) because they form mere 

 continuations or repetitions of the reduced curves, or (2) because 

 the experiments were not numerous enough, nor the theory of 

 the reactions sufficiently evident, to enable the calculation to be 

 made. The curves representing the formation of ferric meco- 

 nate and acetate somewhat resemble, but are not identical with, 

 the cubical parabola. Similar ones are drawn by Harcourt and 

 Esson (Phil. Trans. 1866, pi. 17), and Guldberg and Waage 

 (Etudes sur les Affinites chimiques, Christiania, 1867, pis. 14, 15, 

 16). It is obvious that they represent duplex reactions; but 

 their complete reduction may perhaps be a matter of consider- 

 able difficulty. 



In order to estimate the accuracy of the experimental work, 

 and the soundness of the hypothesis involved in its symbolic 

 expression, I have drawn up the following error Table, showing 



