FORMATION OP INDIGO-BLUE. 221 



The decomposition of indican, after taking up several equi- 

 valents of water, into 1 equivalent of indigo-blue or indirubine 

 and 3 equivalents of indiglucine will be evident at once from 

 a comparison of the formulae of these bodies. 



The formation of leucine will also be easily understood 

 when it is considered that indigo-blue and 10 equivalents 

 of water, contain the elements of 1 equivalent of leucine, 

 1 equivalent of formic acid, and 2 equivalents of carbonic 

 acid, as the following equation will show: — 



( C u H w N0 4 1 eq. Leucine. 

 1 eq. Indigo-blue C lfl H 5 NO, j = C , H, O, 1 eq. Formic acid 



10 eqs. Water H 10 O 10 ) p n o n i -a 



* V Ca 4 2 eqs. Carb. acid. 



Cl ' Hl6N ° 12 CuHuNO,, 



Such a decomposition as this can of course only take place 

 before the elements of indican have arranged themselves in 

 such a manner as to form indigo-blue, which is a body of far 

 too stable a nature to undergo any decomposition by the 

 action of dilute acids. 



In order to explain the formation of indifulvine it is neces- 

 sary to take into consideration the simultaneous formation of 

 formic acid. Indican m&y be supposed, after taking up 5 

 alents of water, to split up into 1 equivalent of a indi- 

 fulvine, 2 equivalents of indiglucine, and 3 equivalents of 



formic acid, as will be seen from the following equation : 



Indican C„ H* NO* j ( C « H "> N0 3 * eq. a Indifulvine. 



Water H, O, j = °» H *> °* 2 ^ 8 ' ^diglucine. 



n „ " V C, H« 0„ 3 eqs. Formic acid. 



C.H..NO,. 



The following equation shows how the other modification 

 of indifulvine may be supposed to take its rise : — 



iC* H lt N, O, 1 eq. b Indifulvine. 

 C« H40 O* 4 eqs. Indiglucine. 

 0,0 H 10 O w 5eqs. Formica 

 C. 0^2 eqs. Carb. m 



Cio« h„ n, :a 



