1867.] 



Extractive Matters of Urine. — Part I. 



99 



If the formula Cgg H^g NO^g be adopted as expressing the composition 

 of the organic substance combined with the oxide of lead, the relation in 

 which the latter stands to the other extractive matters will be easily seen, 

 though the calculated composition does not in this case agree very well 

 in all respects with that deduced from the above analysis. This formula 

 requires 



Calculation. Experiment. 





•228 



45-41 



45-30 





28 



5-57 



6-17 



N 



14 



2-78 



2-63 



0,, 



232 



46-24 



45-90 





502 



100-00 



100-00 



It may excite some surprise that the extractive matter contained in this 

 compound, which was soluble in alcohol, should have been obtained from 

 the brown glutinous mass (a), which was insoluble in alcohol, and had 

 quite the appearance of an extractive matter itself. This may, however, 

 be easily explained, since the mass {a) contained lead, being, indeed, merely 

 a lead compound of the extractive matter soluble in alcohol, and many of the 

 compounds of the latter with bases are insoluble in alcohol. It is, in fact, 

 still doubtful whether urine does contain an extractive matter insoluble in 

 alcoliol, and whether the various substances having this character, ob- 

 tained in these and previous experiments, are not compounds of extractive 

 matters with bases ; but to this point I shall return on a future occasion. 



The ethereal solution (A) contained some extractive matter, and also 

 liydrochloric acid. The latter having been removed by introducing car- 

 bonate of lead and shaking well, there was added after filtration an excess 

 of an alcoholic solution of acetate of lead, which produced a copious pre- 

 cipitate. This was filtered off and then dissolved in a mixture of alcohol 

 and acetic acid. To the filtered solution a small quantity of ammonia was 

 added. The precipitate thereby produced was filtered off and treated as 

 usual before being analyzed. 



VI. 1-2650 grm. of this compound gave 6860 grm. carbonic acid and 

 0-2025 grm. water. 



1-4445 grm. gave 0-0810 grm. chloride of platinum and ammonium. 



0-4610 grm. gave 0'4250 grm. sulphate of lead. 



In 100 parts it contained therefore 



C 14-79 



II 1-77 



N 0-35 



15-26 



PbO 67-83 



10000 



