This acid was prepared by reducing with ammonium sulfide, or with tin and hydrochloric acid, the solution resulting from the treatment of p-xylenesulfonic acid with red, fuming nitric acid. The nitro-acid was not isolated, nor were any of its derivatives prepared. Guy G. Frary2 describes a nitrosulfonic acid of p-xylene which he prepared by nitrating p-xylenesulfonic acid with nitric acid (sp. gr. 1.60) in the cold. The potassium, sodium, calcium, barium, ...
