1867.] 



Extractive Matters of Urine. — Part I. 



103 



B (1S57). 



Having by the previous experiments determined in a general way the 

 composition of tlie precipitate produced in urine by basic acetate of lead, I 

 now resolved to ascertain whether the precipitate witli neutral acetate of 

 lead contains any urinary extractive matter in addition to the sulphate, 

 phosphate, chloride, and urate of lead, of which it chiefly consists. For 

 this purpose acetate of lead was added to urine, and the precipitate thereby 

 produced was washed with water and then treated with an excess of dilute 

 sulphuric acid, with which it was left to stand for some time. To the fil- 

 tered liquid, which had a deep yellow colour, there was added sufficient 

 baryta-water to remove the sulphuric acid, and then an excess of milk of 

 lime, which gave a gelatinous precipitate consisting chiefly of phosphate of 

 lime. The hquid, which had now lost much of its colour, was filtered and 

 made acid with acetic acid. Acetate of lead now produced no precipitate 

 but on the addition of ammonia a cream-coloured precipitate fell, which 

 after being washed was 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 usual manner in a current of air to a syrup. This 

 syrup vras dissolved in cold alcohol, and to the solution there was added 

 an alcoholic solution of acetate of lead. The precipitate thereby produced 

 was filtered off, washed with alcohol, and then treated with dilute sulphuric 

 acid. The excess of the latter having been removed as before by means of 

 carbonate of lead, the filtered liquid was evaporated. The residue which 

 was left was treated with cold alcohol, and the alcoholic solution, after 

 being filtered, was mixed with twice its volume of ether, which caused it 

 to become milky. After some time a glutinous deposit settled at the bot- 

 tom of the vessel, leaving a supernatant liquid, which was bright yellow and 

 clear. To this liquid there was added an alcoholic solution of acetate of 

 lead, which produced a cream-coloured precipitate. This was filtered off, 

 washed with alcohol, dried in vacuo, and analyzed as usual, the results 

 being as follows : — 



I. 0-9805 grm. gave 0-S425 grrn. carbonic acid and 0'2320 grm. water. 



1'1795 grm. gave 0*1850 grm. chloride of platimmi and ammonium. 



Q'Qn^ grm. gave 0"5000 grm. sulphate of lead. 



0*7280 grm. gave 0-0120 grm. chloride of silver, equivalent to 0-016G 

 grm. chloride of lead. 



Hence the compound contained, in 100 parts. 



C. 

 H 

 N. 

 O 



23*43 

 2*62 



0- 9S 

 18-34 

 53-03 



1- GO 

 100-00 



PbO. 



PbCi 



