Abstract: With the present invention a tobacco sheet or foil is proposed which has an elevated filling force and consists of tobacco particles, water, binders and moisturizers, and relatively gas-impermeable, in particular surface-sealed cover layers being connected together by a spongy structure which is formed by gas-filled bubbles, and in which cavities are formed having a shaggy, furrowed and/or torn surface.

Abstract: Fibers of tobacco smoke filters which have been impregnated with dicarboxylic or polycarboxylic acids or anhydrides thereof can be obtained by dissolving anhydrides of dicarboxylic or polycarboxylic acids in volatile or physiologically acceptable organic solvents and applying them to the fibers and, if appropriate, hydrolyzing them with water.

Abstract: Smoking products, for example cigarettes, cut tobacco, pipe tobacco, cigarillos and the like, give an increased yield of nicotine in the tobacco smoke without impairment of the taste of the smoke, when trans-nicotine N'-oxide, which is free or substantially free of cis-nicotine N'-oxide or contains at most 10% by weight of the cis-isomer, is added thereto in a quantity of up to 5% by weight, relative to the dry weight of the tobacco. The nicotine N-oxide is prepared by oxidizing nicotine with an aqueous H.sub.2 O.sub.2 solution in the presence of a catalytic amount of non-oxidizing acid having a pk value of less than 5 to produce an oxidation mixture containing trans and cis-nicotine N'-oxide.