229 



Colouring Principles. 



637. CHRYSOPHANIC ACID. C 10 H 8 3 . 



a. Brilliant golden scales. 



b. Dull yellow nodules, 



c. Bright yellow crystalline scales. 



Note. Specimen a was prepared by Mr. F. J. Hanbury from rhubarb ; 

 specimen b from Goa powder by benzol ; and specimen c from Ooa powder 

 by sublimation ; b and c were prepared by Mr. Postans. See Mat. Med. 

 Catalogue, p. 33, No. 178 ; P. J. [3] , Tol. vii., p. 664. 



