186/.] 



Ewtradive Matters of Urine, — Part I. 



109 



The substance combined with oxide of lead contained, in 1 00 parts, 



C 53-63 



H 5-41 



N 2-99 



37-97 



100-00 



This analysis yielded so large an amount of nitrogen and so little hydro- 

 gen and oxygen as compared with the preceding analyses, that it becomes 

 difficult to bring it into harmony with the latter without having recourse to 

 very improbable hypotheses. This discordance would, however, not be 

 sufficient to justify the conclusion that the extractive matter soluble in 

 ether contained in the precipitate with ammonia has a different composi- 

 tion from that prepared in the same way from the two other lead precipi- 

 tates. By subsequent experiments it was indeed rendered very probable 

 that they are identical in composition. It may therefore be inferred that 

 in this case the discrepancy was due to some error, perhaps analytical. I 

 should have hesitated in giving the details of this analysis had I not been 

 desirous of presenting, without making any selection, the whole of the evi- 

 dence on which my final conclusions are based. 



The syrup-like deposit (c), insoluble in ether, was dissolved in alcohol. 

 The solution was mixed with an alcoholic solution of acetate of lead, and 

 the precipitate thereby produced was filtered ofp, washed with alcohol, and 

 treated with dilute sulphuric acid. The excess of acid was removed by 

 means of carbonate of lead, and the filtered liquid was evaporated in the 

 air-current. The residue left on evaporation was treated with cold water, 

 which left a quantity of chloride of lead undissolved ; and to the filtered 

 liquid there was added acetate of lead, and then a large quantity of alcohol. 

 This gave a precipitate which, after being treated in the usual manner, was 

 analyzed, the results obtained being as follows : — 



II. l'1540grm. gave 0*6320 grm. carbonic acid and 0*2050 grm. water. 



1*7405 grm. gave 0*2700 grm. chloride of platinum and ammonium. 



0*3005 grm. gave 0*2570 grm. sulphate of lead. 



0*7200 grm. gave 0*1015 grm. chloride of silver, equivalent to 0*0986 

 grm. chloride of lead. 



In 100 parts it contained therefore 



C 14'93 



H 1*97 



N 0*97 



O.. 16*51 



PbO 51*92 



PbCl 13*70 



100*00 



The substance combined with oxide and chloride of lead contained, in 

 100 parts, 



