Nitric Acid On Tin

In a paper read Lore the London Chemical society by C. H. Walker on the action of nitric acid on tin, some of the prevalent ideas on that subject are shown to be singularly erroneous. Among these is the general supposition that metallic tin dissolves in nitric acid with the production of both a stannous and stannic salt, according to the conditions of temperature and concentration of the acid. In these later experimente - made to determine the amounts of stannous salts f ormed under various conditions of temperature, coneentration of acid and mass of tin treated - it is shown that with diluto acids the increase of temperature has but little effect, but with more concentrated acids the effect is more marked, for the alteration of a few more degrees will reduce the amount of stannous salt to nothing, while increase of concentration, other things being equal, decreases the proportion of stannous salt. It is found that the yellowish white substance f onned from centrated solutions is a hydrated stannic nitrate of varying compositiou, depending on tho time betrween production and analysis, also on the method of purification adopted for eliminating the nitric