130 



Mr. E. Schunck on the Colouring and 



[Hecessj 



amorphous substance, transparent in thin layers, brittle when quite dry, 

 but becoming soft and riscid on exposure to the air. Its taste was acidj 

 followed by a bitter after-taste. When heated it swelled up, gave off mucli 

 gas, and left a bulky charcoal, which was easily reduced to a white ash. A 

 determination of the quantity of ash yielded the following results : — 



0*5005 grm. dried in the water-bath left 0*0120 grm. ash = 2*39 per 

 cent. 



The ash was non-alkaline, entirely insoluble in water, but soluble in 

 hydrochloric acid, and consisted of alumina with traces of oxide of iron and 

 lime. The substance was completely insoluble in boihng absolute alcohol ; 

 but on adding a little concentrated sulphuric acid, the liquid acquired a 

 deep yellow colour, and nearly the whole of the substance dissolved gradu- 

 ally, though not so easily as in the preceding case. The alcoholic solution, 

 on being mixed with several tim.es its volume of ether, separated into two 

 layers, the lov/er one being of a deep yellow colour, and containing appa- 

 rently the whole of the extractive matter, while the supernatant ethereal 

 liquid was almost colourless. The watery solution, when tried in the usual 

 manner, was found to contain no trace of glucose. In this case, therefore, 

 the substance consisted of extractive matter only, in combination with 

 alumina. Avery small amount of the latter is sufficient, as it appears, to 

 produce with the extractive matter a compound insoluble in alcohol. 



Some of the cream-coloured lead compound, which had served for 

 Analysis III. Series G, and which had been prepared from a substance 

 insoluble in alcohol, was treated with a mixture of alcohol and sulphuric 

 acid. The liquid, on being left to stand in contact with the compound, 

 gradually acquired a bright yellow colour like that of a solution of ex- 

 tractive matter, while the resulting sulphate of lead appeared almost white. 



These experiments lead to the conclusion that there exists no urinary 

 extractive matter insoluble in alcohol, and that what has hitherto been 

 so called consists generally of a compound of the extractive matter soluble 

 in alcohol, with some base or with several bases mixed occasionally with 

 similar comipounds of the glucose, which so often accompanies this extractive 

 matter, and is probably one of its products of decomposition. Though 

 the extractive matter soluble in ether forms, with bases, compounds in- 

 soluble in alcohol, I have never found this substance to be a constituent of 

 the product insoluble in alcohol when prepared in the manner above 

 described. 



I shall now proceed to give my views of the composition of the uncom- 

 bined urinary extractive matters, as deduced from the analytical determi- 

 nations contained in the first part of this paper. 



For the extractive matter soluble in alcohol and ether when in its 

 highest state of purity I have adopted the formula Cgg 11.^ NO.^. The 

 Analyses III. Series A, L Series F, I. Series G, and I. Series H gave 

 numbers agreeing tolerably well with this formula, as the following 

 Table, in which the results are placed together for the sake of a more 



