120 



Mr. E. ScliurLck on the Colouring and 



[Recess^ 



the extractive matters. This was then added to the lead precipitate pro- 

 duced hy ammonia in the urine after being filtered from the precipitate with 

 acetate of lead. The mixture contained, therefore, the extractive matters 

 of the three lead precipitates, which had before been separately examined. 

 It was treated in the manner described near the conclusion of the preceding 

 section, that is to say, it was acted on by dilute sulphuric acid ; the hydro- 

 chloric acid set at liberty was removed bj^ means of sulphate of silver, the 

 excess of silver was precipitated as sulphide, the sulphuric acid was got rid 

 of with carbonate of lead, and the lead in solution having been precipitated 

 with sulphuretted hydrogen, the liquid was evaporated, leaving a residue 

 containing the extractive matters, which were separated from one another 

 by means of alcohol and ether. In this way I obtained a substance soluble 

 in alcohol and ether («), a second soluble in alcohol but insoluble in ether 

 (5), and a third insoluble in alcohol and ether (c). From the first a lead 

 compound was prepared in the usual manner, the analysis of which led to 

 the following results : — 



I. 0*9.530 grm. gave 0*6G95 grm. carbonic acid and 0"1()65 grm. water. 



r3260 grm. gave O"0995 grm. chloride of platinum and ammonium. 



0*5250 grm. gave 0*4500 grm. sulphate of lead. 



In 1 00 parts it contained therefore 



The substance com.bined with oxide of lead contained, in 100 parts, 



It will be seen that the composition of the extractive matter of this com- 

 pound may be expressed by "the formula Cgg Hg^ NO-,, the same to which 

 Analysis III. Series A led. 



The substance h was treated in the cold with absolute alcohol, which 

 left a portion of it undissolved. The solution was evaporated, and the resi- 

 due was treated as before with absolute alcohol. The residue left after the 

 second evaporation was dissolved in water. Acetate of lead was added to 

 the solution, and the filtered liquid was mixed with alcohol, which pro- 

 duced a precipitate. This was treated as usual and then analyzed. 



II. 1*0980 grm. gave Ov935 grm. carbonic acid and 0*2410 grm. water. 



1*6135 grm. gave 0*2/40 grm. chloride of platinum and ammonium. 



0*4765 grm. gave 0*3550 grm.. sulphate of lead. 



C, 

 H... 

 N... 

 O.. 



PbO 



19*15 

 1-94 

 0*47 

 15*37 

 63*07 

 100*00 



C .. 

 H.. 

 N.. 



O 



51-88 

 5-25 

 1*27 

 41*60 

 100 00 



