1867.] 



Extractive Matters of Urine. — Part I. 



125 



Hence it follows that tlie substances b and c have the same composi- 

 tion, a composition corresponding with the formula C33 H^- NO32, the same 

 to which xlnalysis II. of the preceding series conducted. 



The substance d was treated with cold water. The resulting dark- 

 brown solution was filtered from some gelatinous matter, which remained 

 undissolved and was found to consist chiefly of silica, and then mixed with an 

 excess of acetate of lead. This produced a dark-brown precipitate, which 

 was filtered off. A little ammonia and a large quantity of alcohol were then 

 added to the liquid, and the bulky cream-coloured precipitate produced 

 was filtered off, washed with alcohol, suspended in water, and decomposed 

 with sulphuretted hydrogen. The filtered hquid was evaporated, and the 

 brown glutinous residue vvhich was left was dissolved in water. The addi- 

 tion of acetate of lead to the solution produced a brown precipitate. The 

 filtered liquid gave, on being mixed with alcohol, a cream-coloured preci- 

 pitate, which was filtered off, washed, dried, and analyzed as usual. 



IV. 1*1760 grm. gave 0'944o grm. carbonic acid and 0'31 65 grm. water. 



1*6280 grm. gave 0*5300 grm. chloride of platinum and animonium. 



0*6715 grm. gave 0*4330 grm. sulphate of lead. 



In 100 parts it contained therefore 



C 21*90 



H 2*99 



N 2*04 



O 25*63 



PbO , 47-44 



100-00 



The substance combined with oxide of lead contained, in 100 parts, 



C 41*66 



H 5-68 



N 3-88 



47-78 



100-00 



The unusually large amount of nitrogen yielded by this analysis was 

 probably due to an admixture of the impurity which in the former experi- 

 ments was removed by means of oxide of mercury, and which contains, as 

 I have shown, more than seven per cent, of that element. Had I employed 

 the same method of purification as before, the composition would probably 

 have corresponded more closely with that to which Analysis III. of the 

 preceding series and several previous determinations led, and which may 

 be represented by the formula Cg^ H.^g ^^■n- 



The numerical results obtained by these determinations are, I think, 

 sufficiently numerous and concordant to allow of definite conclusions being 

 drawn regarding the composition of the urinary extractive matters. 



