64 



Appendix. 



2. Farther oxidation to dioxyanthraquinone."' 



Succcessive Siibstituions. 



H- 



-C 



C 



// \. // % 



H-C C C- 



I II I 



H-C C C 



^ / \ ^ \ 



c c C— 



I i II 



H C C- 



I w / 



H C 



I 

 H 



Anthracene, Cj^Hj„. 



Anthraquinone, Cj^H^Oj 



SO,H 

 SO.H 



OK 

 OK 



OH 

 OH 



O 



I 

 O 



Dioxyanthraquinone or Alizarin, Cj4Hp(OH)20^. 



The history of this triumph may be indicated as follows •}"' 



(21) Fu-st, C,4Hia+30=C,4H80.3 + H20. 



Second, C,,H80,+2HjS04=C,4H6(HSO;,)20,+2H,0. 

 Ci4H6(HS03)20, + GKHO = Ci4H6(OK),0, + 



[2K2SO:,-i-4H,0. 

 C,4H6(OK).,0,+2HCl=C,4H6(OH),02+2KCl. 



(22) Artilicial prodcution of Alizarin: Roscok: Chem. iVeirs, xxi., I.S.'); 

 AnuT. Reprint, p. :«2(1870). 



