218 MR. E. SCHUNCK ON THE 



of lead the composition of indiglucine is expressed by the 

 formula C 12 H 9 On, and that hence its formula when in an 

 uncombined state is probably C 12 H 10 12 . 



An analysis of the lead compound, prepared by adding 

 acetate of lead and ammonia to a watery solution of indi- 

 glucine, filtering, washing and drying in vacuo, gave the 

 following results: — 



0.5640 grm. burnt with chromate of lead gave 0.2430 grm. 

 carbonic acid and 0.0845 water. 



0.2495 grm. gave 0.2445 grm. sulphate of lead. 



These numbers lead like those of the former analyses to 

 the formula C ]2 H 9 On +4 Pb O, as will be seen by com- 

 paring the numbers required by theory with those deduced 

 from the analysis. 



Eqs Calculated. Found. 



Carbon 12 72 11.69 11.75 



Hydrogen 9 9 1.46 1.66 



Oxygen 11 88 14.30 14.49 



Oxide of Lead 4 446.8 72.55 72.10 



615.8 100.00 100.00 



There still remain some products of the action of acids on 

 indican to be treated of. These products are volatile. In 

 order to ascertain their nature I took a solution of indican, 

 mixed it with sulphuric acid and boiled it in a retort, the tube 

 of which passed through a cork into a receiver from which a 

 tube led into a bottle with lime water, the joinings being all 

 air-tight. After the liquid had entered into a state of ebul- 

 lition and the air had been expelled from the apparatus, bub- 

 bles of gas were seen now and then to pass through the lime 

 water, which became milky and deposited a quantity of car- 

 bonate of lime. After a great part of the solution had been 

 distilled, the receiver was removed and the liquid contained in 

 it, which was yellowish and had an acid reaction, was mixed 



