1867.] 



E attractive Matters of Urine, — Part I. 



83 



however, in discovering two new facts, to which I attach some importance. 

 The first is, that the composition of the brown pulverulent substance, 

 which is little soluble in alcohol, stands in a definite relation to that of 

 indigo-blue ; the second, that the urine, after depositing these flocks and 

 being made alkaline, has acquired the property of reducing oxide of copper, 

 from which it may be inferred that it contains glucose in solution. As the 

 analytical details which led to the discovery of the first fact have not 

 hitherto been published, I think this a fitting occasion for making them 

 known. 



The brown pulverulent substance was prepared in the following manner : 

 ■ — Urine was mixed with hydrochloric acid and allowed to stand. The 

 uric acid which was deposited was separated by filtration, and the liquid 

 was boiled for som^e time. The black powder v»'hich separated during the 

 boiling was filtered off, washed with water, dried, and treated with cold 

 alcohol, which extracted the easily soluble resinous portion, thereby 

 acquiring a brown colour. The portion left undissolved by the cold alcohol 

 was dissolved in boiling alcohol to which a little ammonia was added. The 

 brown solution was filtered and mixed with an excess of hydrochloric acid, 

 which produced a brown precipitate, the supernatant liqu ici remamms,' 

 coloured. This precipitate v/as collected on a filter, washed with cold 

 alcohol until the acid and sal-ammoniac were removed, and dried. It had 

 then the appearance of a dull, black, amorphous mass, which yielded a 

 brownish-black powder, strongly resembling some of the products of de- 

 composition of indican. When heated in a crucible it gave off a smell like 

 that of burning horn, and then burned without previously fusing, giving 

 much charcoal, which disappeared without leaving any ash. I need not 

 describe its other properties, as they are in no way characteristic or inter- 

 esting. Its composition, which is a matter of more importance, was deter- 

 mined by several analyses, the results of which are as follows : — ■ 



I. 0*4305 grm., dried at 100° C. and burnt with oxide of copper and 

 oxygen, gave 0"9720 grm. carbonic acid and 0'1985 grm. water. 



0"58i5 grm., heated with soda-lime, gave 0*4190 grm. platinum. 



IL 0"3850 grm., prepared on another occasion, gave 0'87G0 grm. car- 

 bonic acid and 0*1755 grm. water. 



0*5315 grm. gave 0*3685 grm. platinum. 



These numbers lead to the formula C^^ IL NO^, which requires — 



Experiment. 



Calculation. 



Cj, 84 61-31 



H,...,.. 7 5*10 



N 14 10*21 



O 32 23*38 



I. 



II. 



61-57 



62*05 



5-12 



5*06 



10*23 



9-85 



23-08 



23*04 



100*00 



100-00 



137 100-00 



Now the formula C^^ H. NO^ is also that of anthranilic acid, the acid 



