.1887.] 



Extractive Matters of Urine. —~Ps.Tt I. 



95 



On being dried, the syrup became hard, but dehquesced again on exposure 

 to the air. 



The ethereal hquid (e) containing in solution that portion of the extractive 

 matter of the lead precipitate (6) soluble in ether, was agitated with carbonate 

 of lead, by which means the hydrochloric acid contained in it was entirely 

 removed. To the filtered liquid there was added an alcoholic solution of 

 acetate of lead, which produced a cream-coloured precipitate. This was 

 filtered off, washed with cold alcohol, dried ^?^ vacuo, and analyzed, the re- 

 sults obtained being as follows : — 



III. 1 -3455 grm. gave 1*0425 grm. carbonic acid and 0'2730 grm. water. 



1*5580 grm. gave 0*1385 grm. chloride of platinum and ammonium. 



0*7565 grm. gave 0*6025 grm. sulphate of lead. 



The compound contained therefore, in 100 parts, 



C 21-13 



H 2-25 



N 0*55 



O 17*47 



PbO 58*60 



100-00 



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

 lead, agrees tolerably well with the formula Cgg 11-^ NOg^j which requires 



Calculation, Experiment. 



C,6 516 51*75 51*04 



H., 51 5*11 5*43 



n" 14 1*40 1*34 



O5, 416 41*74 42*19 



997 100*00 100^ 



In the case of a compound like this, having such a high atomic weight, 

 several formulae may of course be calculated, each of v/hich may give a 

 theoretical composition agreeing as well as the above with that found by 

 experiment. My reasons for adopting the one just given will be stated 

 further on. 



A portion of the liquid from which this compound was precipitated 

 with acetate of lead was evaporated, when it left a brown syrup closely 

 resembling that obtained from the liquid from which the lead compound 

 of the second analysis was precipitated. When heated in a crucible it 

 gave off copious fumes, and left off much charcoal, which, however, burnt 

 away, leaving only a trace of ash. Its watery solution had a strongly acid 

 reaction, though it was quite free from hydrochloric acid. When treated 

 with boihng caustic soda lye it evolved ammonia. The watery solution, 

 on the addition of a salt of copper and an excess of caustic alkali, became 

 green, and the filtered hquid, on being boiled, deposited an abundance of 



