302 Dr. Schunck on some Products 



in the process ; but it is not easy to see whence the carbonic 

 acid is derived. I think, however, it may originate in the 

 formation of anthranilic acid. This acid, as is well known, 

 is produced by the action of caustic alkalies on indigo-blue, 

 which, taking up water and oxygen, yields anthranilic acid and 

 carbonic acid, in accordance with the following equation :— 



Indigo-blue. Anthranilic acid. 



16 H 5 N0 2 +aHO+ 4 0=C u H 7 N0 4 + 2 C0 2 . 

 The oxygen in this case must be derived from water, the 

 hydrogen of which, instead of being set at liberty, probably 

 unites with a portion of the indigo-blue, forming reduced 

 iudigo, which dissolves in the caustic alkali. Hence the par- 

 tial reduction and solution of the indigo -blue, which, as men- 

 tioned above, is observed at the commencement of the process. 

 The carbonic acid does not, as might naturally be supposed, 

 combine with the alkali, but unites in statu nascenti with 

 alcohol, acetic acid, and a portion of the indigo-blue to form 

 the body A. That it should do so in the presence of an 

 excess of alkali is not more surprising than that acetic acid 

 should, under the same circumstances, leave the base with 

 which it is combined in order to form a perfectly neutral body 

 — a fact of which there can be no doubt. 



B. 



Of this body also two series of analyses were made, the 

 material being obtained at the same time as that of the two 

 series of A. The first series yielded the following results : — 



I. 0*3315 grm. gave 0*8925 grm. carbonic acid and 0*2465 

 grm. water. 



0*5270 grm. gave 0*2645 grm. chloride of platinum and 

 ammonium. 



II. 0*3330 grm. gave 0*9015 grm. carbonic acid and 0*2445 

 grm. water. 



0*5420 grm. gave 0*3190 grm. chloride of platinum and 

 ammonium. 



III. 0*3390 grm. gave 0*9195 grm. carbonic acid and 0*2530 

 grm. water. 



0*5230 grm. gave 0*2625 grm. chloride of platinum and 



ammonium. 



These numbers correspond with the formula C 52 H 35 N0 8 , 



which requires 



Experiment. 



Calculation. I. II. HI: 



C.,2 3* 2 73'4 f 73'4 2 73^3 73"97 



H 33 35 8-23 8-26 8*15 8-29 



N H 3**9 3i5 3' 6 9 3i5 



O a 64 1507 15*17 14*33 H'59 



425 IOO'OO 



