Abstract: A cigarette mouthpiece of substantially cylindrical configuration assembled of two identical semi-cylindrical sections disposed in mutual concavely facing relationship with each longitudinal edge of one section in abuttment with a different one of the longitudinal edges of the other section. When assembled into a mouthpiece, the semi-cylindrical sections cooperate to define a plurality of generally longitudinally extending air ventilation grooves equally spaced from each other around the perimeter of the mouthpiece and a plurality of smoke flow capillaries extending generally longitudinally through the mouthpiece.

Abstract: Improved palladium-containing smoking tobacco compositions wherein the palladium in a highly active form is obtained by depositing on the tobacco palladium which has been insolubilized by admixing in an aqueous medium a water-soluble palladium compound and a reducing agent capable of reducing dissolved palladium cations to insoluble palladium. Methods for determining the amount of insoluble or active palladium are described.

Abstract: The concentration of polycyclic aromatic hydrocarbons in tobacco smoke is reduced by incorporating palladium, either in metallic form or as a salt, and an inorganic nitric oxide generating compound into tobacco.

Abstract: The stability of palladium in tobacco casing systems is improved by the incorporation of a polysaccharide protective colloid.

Abstract: The amount of polycyclic aromatic hydrocarbons in tobacco smoke is reduced and a substantially diminished biological activity of the tobacco smoke condensate is achieved by adding to the tobacco palladium, either in metallic or salt form, and an inorganic nitric oxide generating compound.

Abstract: A smoking composition comprising tobacco and a catalytic agent for causing a decrease in the yield of polycyclic aromatic compounds arising from pyrolytic reactions of the composition, the agent being selected from the group consisting of finely divided unsupported metallic palladium or palladium salts which are heat decomposable into metallic palladium.

Abstract: The amount of polycyclic aromatic hydrocarbons in tobacco smoke is reduced and a substantially diminished biological activity of the tobacco smoke condensate when evaluated on experimental animals following conventional protocol is achieved by adding to the tobacco palladium, either in metallic or salt form, and an inorganic nitric oxide generating compound.