70 Botanic Drugs 



is an irritant antiseptic sometimes applied exter- 

 nally in chronic skin diseases, 1 to 8 of lard; but it 

 has been absorbed from the surface with fatal re- 

 sults. BISMUTH SUBGALLATE is given in 2- to 

 8-grain doses. Its real use is, either in official form 

 or as DERMATOL, as a dusting powder. It is little 

 liable to absorption. 



SALICYLIC ACID NATURAL. This acid is 

 derived from the natural oils of wintergreen and 

 sweet birch. As at first made, the synthetic sali- 

 cylic acid was impure, containing cresylic acids. 

 These were later removed by improvements in 

 processes. Then it was stated that cresotinic acids 

 exist in the synthetic product, which is stating much 

 the same thing in another way. Now as a matter of 

 fact, the synthetic acid can be entirely freed from 

 these impurities and the resultant acid have ex- 

 actly the same chemical formula as has the natural 

 acid, and doubtless some of the purer grades of the 

 synthetic acid are marketed quite free from these 

 slowly paralyzant impurities. 



But there are many difficulties as regards the 

 graphic formulae of the salicyl and benzoyl com- 

 pounds. From this point of view, salicylic acid is 

 an or^o-oxybenzoic acid, and assuredly so as pre- 

 pared from wintergreen. Now three oxybenzoic 

 acids are known, differing in the relative positions 

 of their side claims ortho, meta, and para oxyben- 

 zoic acids. Only the first is really active, the other 

 two having feeble actions. Salicylic acid has two 

 side chains, and there are few agents in the materia 

 medica offering similar opportunities for the making 

 of new products by substituting various groups in 



