114 



Mr. E. Scliunck on the Colouring and 



[E^ecessj 



lead compound, but the quantity obtained 7/as not sufficient for a complete 

 analysis. 



The precipitate with basic acetate of lead was submitted to a process 

 which did not differ from that just described, except in being rather simpler 

 on account of the absence of phosphoric acid. It yielded by this treatment 

 "four substances ; viz. one soluble in ether («), a second soluble in alcohol 

 but insoluble in ether {h), a third insoluble in a mixture of alcohol and 

 ether (c), and a fourth insoluble in alcohol as v/ell as in ether (J). The 

 substance soluble in ether («) was dissolved in absolute alcohol, and to the 

 solution there was added an alcoholic solution of acetate of lead, which gave 

 a precipitate of the usual colour. This was filtered off and prepared in the 

 same manner as before for analysis. 



II. 0"7215 grm. of this compound gave 0"6155 grm. carbonic acid and 

 0*1695 grm. water. 



1*1295 grm. gave 0*1215 grm. chloride of platinum and ammonium. 



0*4820 grm. gave 0*3680 grm. sulphate of lead. 



In 100 parts it contained therefore 



C ' 23*26 



H 2*61 



N 0*67 



O 17-29 



PbO 56*17 



100*00 



The substance combined with oxide of lead contained, in 100 parts, 



C 53*06 



H ^*95 



N 1*52 



O 39*47 



100*00 



The composition of the substance, combined in this case with oxide of 

 lead, differs, as will be seen, very widely from that of the extractive matter 

 soluble in ether as determined by previous experiments. This want of ac- 

 cordance is surprising, and I can only attribute it to some error in the ana- 

 lysis. The ratio between the nitrogen, the carbon, and the hydrogen is 

 about the same as usual, and the discrepancy may therefore have arisen 

 from an error in the estimation of the oxide of lead. There was not suffi- 

 cient material left for another determination. 



The substances (5) and (c), which I supposed to be essentially the same, 

 were dissolved together in absolute alcohol. The solution was filtered from 

 a sm.all quantity of insoluble matter, and there was added to it an alcoholic 

 solution of acetate of lead, which produced a precipitate of the usual colour. 

 This was filtered off, washed, dried, and analyzed v/ith the following 

 results : — 



