1911 Encyclopædia Britannica (1911)
“ Salicyclic acid is not absorbed by the skin, but it rapidly kills the cells of the e idermis, without affecting the immediately subjacent cells of the drermis (“ true skin ”) . It has a very useful local anhidrotic action. Salicylic acid is a powerful irritant when inhaled or swallowed in a concentrated form, and even when much diluted it causes pain, nausea and vomiting. When salicin is taken internally no irritant action occurs, nor is there any antisepsis. Whatever drug of this group be taken, the product absorbed by the blood is almost entirely sodium salicylate. ”
