A challenge : Bisolvon meets, at mucous gland level, the challenge of the thick, tenacious, non-purulent sputum so characteristic of the chronic bronchitic.

Licence: In copyright

Credit: A challenge : Bisolvon meets, at mucous gland level, the challenge of the thick, tenacious, non-purulent sputum so characteristic of the chronic bronchitic. Source: Wellcome Collection.