ACIDUM CHRYSOPHANICUM. 231 



Characters. A powder or in small pieces of a light yellow 

 colour, becoming pale-brown by exposure ; mixed with small 

 pieces of wood. 



Composition. Goa powder contains 80 per cent, of chrys- 

 arobin, C 3o H 26 07, which is converted into chrysophanic acid,, by 

 the process presently to be given. 



From Goa Powder is prepared : 



Acidum Chrysophanicum. Chrysophanic acid C4iHi 04. 

 Made by exhausting Goa powder with hot Benzol, 

 filtering, allowing Chrysarobin to crystallise out, dis- 

 solving this in strong Potash, and decomposing with 

 a mineral acid. It may also be obtained from 

 Rhubarb. See Rhei Radix, page 318. 



Characters. A dull orange-yellow powder, or shining 

 yellow needles, odourless, with an acrid taste ; insoluble in 

 water, and spirit ; soluble in hot benzol, oils, and vaseline. 



Dose.& to 2 gr. 



Preparation. 



tlngnentiim Acidi Ciirysophanici. Vnguen- 

 tum Chrysarobini (U.S.P.). 1 in 10 of benzoated lard. 



ACTION AND USES. 

 1. IMMEDIATE LOCAL ACTION AND TJSES. 



Externally. Goa powder or chrysophanic acid destroys 

 low vegetable organisms in connection with the skin, stains it 

 yellow, and stimulates it so much as to produce in some in- 

 stances serious constitutional disturbance. It is a successful 

 application in some forms of ringworm, and in scaly diseases 

 of the skin, especially psoriasis. 



Internally. Chrysophanic acid is apt to cause vomiting 

 and purging. 



2. ACTION ON THE BLOOD ; SPECIFIC ACTION ; AND REMOTE 

 LOCAL ACTION AND USES. 



Chrysophanic acid has been given with various degrees of 

 success in psoriasis, apparently by a remote local action on the 

 skin. 



Senna Alexandrina ALEXANDRIAN SENNA. 

 The leaflets of Cassia lanceolata and Cassia obovata, 

 imported from Alexandria ; carefully freed from the 



