96 



Mr. E. Sclmnck on the Colouring and 



[Recess^ 



suboxide of copper. This reaction was, however, due to some substance 

 accompanying the extractive matter. On adding to the alcohohc solution 

 of the syrup an alcohohc solution of acetate of lead, a cream-coloured pre- 

 cipitate was produced which contained none of this substance; but on 

 adding ammonia to the filtered liquid, a white precipitate fell in which it 

 was contained in combination with oxide of lead. The lead compound 

 analyzed was therefore free from this impurity, and probably contained 

 merely the urinary extractive matter soluble in alcohol and ether. The 

 watery solution of the syrup, on being mixed with hydrochloric acid and 

 boiled, becam.e darker in colour, and then deposited dark brown resin-like 

 masses, which remained in a state of fusion as long as the hquid was kept 

 boiling. The filtered liquid left on evaporation a syrupy residue, which 

 w^as only partly soluble in water, a quantity of the resin-like substance 

 being left undissolved. The solution, after being again filtered and evapo- 

 rated, left a brown syrup filled with crystalhne needles. Cold alcohol 

 dissolved the greatest part of this residue, leaving only the crystalline 

 needles undissolved. The resinous substance, after being well washed 

 with water, was treated with cold alcohol, in which it was entirely soluble, 

 forming a brown solution which, on evaporation, left a brown, shining, 

 brittle residue. The extractive matter contained in this compound differs 

 therefore from that of the lead compound previously analyzed, not only by 

 its solubility in ether, but also by its yielding with acids products of de- 

 composition of a different kind. 



The alcoholic hquid filtered from the lead precipitate (jb) was mixed 

 with more acetate of lead and some ammonia, with Avhich it gave a bulky 

 cream-coloured precipitate. This was filtered off, washed with water, 

 then suspended in water, and decomposed with sulphuretted hydrogen. 

 The filtered liquid was evaporated, as before described, by means of a 

 current of air, and the yellow syrup left on evaporation was poured into a 

 flask and agitated with alcohol, which dissolved the whole of it with the 

 exception of a slight residue, consisting of a glutinous substance mixed 

 wdth some white crystals. The filtered liquid was evaporated, and the 

 residue left was agitated with ether. The ether having been poured off, 

 the insoluble portion was treated with cold alcohol, which dissolved almost 

 the whole of it. The solution was mixed with a little alcoholic solution 

 of acetate of lead, and the precipitate thereby produced having been 

 filtered off, more acetate of lead was added, which gave a precipitate of a 

 pure cream-colour. This was filtered off, washed with alcohol, dried in 

 vacuo, and analyzed, the following results being obtained : — 



IV. 1'0155 grm. gave 0"6730 grm. carbonic acid and 0'2055 grm. 

 water. 



1'1440 grm. gave 0-1425 grm. chloride of platinum and ammonium. 

 0-4165 grm. gave 0-3180 grm. sulphate of lead. 



0-8905 grm. gave 0*0290 grm. chloride of silver, equivalent to 0-0282 

 chloride of lead. 



