Active Ingredients. - These appear to be much the same as those of turpentine.

Physiological Action. - Similar to that of turpentine and co-paiva, but more irritating to the genito-urinary passages.

Therapeutic Action. - Canada balsam may be resorted to in mucous discharges from the urino-genital organs, such as gleet, gonorrhoea, leucorrhcea, and chronic cystirrhcea. It is useful also in certain forms of chronic rheumatism, especially lumbago and sciatica; and in chronic catarrh, whether pituitous or mucous, occurring in old persons of lax fibre and lymphatic temperament.

Preparations And Dose. - Canada balsam may be given in doses of five to twenty grains in pills or emulsion. The only officinal preparations are Charta Cantharidis; Collodium cum cantharide; and Collo-dium Flexile.