40G 



Professor T. E. Thorpe 



[May 4, 



Table showing that in fritts high percentages of lead are compatible with 

 relatively low solubility of the lead. 



Fritt M, .. 



„ M„ .. 



„ B 103a 



„ B 102a 



„ B 103 



„ W,.. 



„ B 102 



„ A .. 



„ B3a 



„ B3.. 



„ B2a 



„ B2.. 



„ Bl.. 



Percentage 



of Lead oxide in 



fritt. 



36-2 



364 



40-4 



40-7 



413 



41 



II 



41 



47 



lit 



52 



53 



59 



Solubility 



per cent, on 



fritt. 



0-8 



Further inquiry elicited the fact that the extent to which the fritt 

 gave up lead to the solvent depended upon two conditions — 



(1) The existence of a definite numerical relation between the 

 basic and acidic oxides in the fritt, and 



(2) Complete chemical union. 



The proof of the first fact is seen in the following table : 



Table showing dependence of amount of lead oxide dissolved from a fritt 

 by • 25 per cent. HCl upon the value of the ratio — 



Basic oxides (as PbO) 



