LEAD. 129 



Still a third series by Turner establishes the ratio between the nitrate 

 and the sulphate, a known weight of the former being in each experi- 

 ment converted into the latter. One hundred parts of sulphate represent 



of nitrate: 



109.312 

 109.310 

 109.300 



Mean, 109.307, .002 



In all these experiments by Turner the necessary corrections were 

 made for weighing in air. 



In 1846 Marignac* published two sets of determinations of only 

 moderate value. First, chlorine was conducted over weighed lead, and 

 the amount of chloride so formed was determined. The lead chloride 

 was fused before weighing. The ratio to 100 Pb is given in the last 

 column : 



20.506 grm. Pl> gave 27.517 PbCl 2 . 134.190 



16.281 " 21.858 " 134.225 



25.454 34.H9 " '34.159 



Mean, 134.19^ .013 



Secondly, lead chloride was precipitated by silver nitrate and the ratio 

 between PbCl, and 2AgCl determined. The third column gives the AgCl 

 formed by 100 parts of PbCl 2 : 



12.534 grm. PbCl 2 gave 12.911 AgCl. 103.01 



14.052 14.506 " JO3.23 



25.533 " 26.399 " 103.39 



Mean, 103.21, .0745 



For the ratio between lead chloride and silver we have a series of re- 

 sults by Marignac and one experiment by Dumas. There are also un- 

 available data by Turner and by Berzelius. 



Marignac,t applying the method used in his researches upon barium 

 and strontium, and working with lead chloride which had been dried at 

 200, obtained these results. The third column gives the ratio between 

 PbCl 2 , and 100 parts of Ag: 



4.9975 grm. PbCl 2 = 3.8810 grm. Ag. 128.768 



4.9980 " 3.8835 " 128.698 



5.0000 3.8835 " 128.750 



5.0000 " 3.8860 " 128.667 



Mean, 128.721, .016 



Dumas, J in his investigations, found that lead chloride retains traces 



*Aun. Chern. Pharrn., 59, 289; and 290. 1846. 

 t Journ. fiir Prakt. Chem., 74, 218. 1858. 

 I Ann. Chem. Pharm., 113, 35. 1860. 



