1867.] Chemistry. 397 



then renders the solution strongly alkaline with caustic soda, and 

 boils for several hours. Cadmium only is deposited. 



To separate the sulphides of cadmium and copper, the author 

 dissolves in hydrochloric acid and adds chlorate of potash. The 

 solution may then he treated as above, and the copper recovered 

 from the filtrate, by first oxidizing aqua regia, and then precipi- 

 tating with caustic potash. 



Dr. E. Wagner gives * a " Hydrostatic test for the detection 

 of Paraffin in Bees' Wax." The specific gravity of pure bees' wax, 

 he finds to be from 0*965 to 0*969 ; and of commercial paraffin 

 from 0*869 to 0*877. Mixtures of the two will of course give 

 intermediate gravities ; and in the author's experiments the results 

 closely agreed with those required by calculation. Pure bees' wax, 

 it is added, should sink in spirit of wine, sp. gr. 0*961 : if the wax 

 should float, the presence of paraffin may be suspected. 



The same author gives a ready means of detecting stearic acid 

 in paraffin. An alcoholic solution of neutral acetate of lead gives 

 no precipitate in a boiling alcoholic solution of paraffin ; but if 

 stearine is present, a turbidity or flocculent precipitate is produced. 



Dr. Wagner also shows that the density of a specimen may 

 afford some information on the probability of the adulteration of oil 

 of bitter almonds with nitrobenzol. The former has the sp. gr. 

 1040-1*014, the density of ordinary nitrobenzol varies from 1*180 

 to 1*201. A better test, however, is a strong solution of bisulphite 

 of soda, with which genuine oil of bitter almonds forms a crystalline 

 mass. On carefully adding a little water, the nitrobenzol will float 

 on the surface.! 



Proceedings op the Chemical Society. 



At the meeting on March 7th, Mr. E. T. Chapman read a 

 paper "On the Oxidation of Formic Acids." This acid, unlike 

 those of the acetic and aromatic series, the author has found does 

 not resist the oxidizing action of a solution of chromic acid, which 

 converts it into water and carbonic acid. 



Dr. Dupre afterwards read a " Note on the Synthesis of Formic 

 and Hyposulphurous Acid." Formic acid is produced by the action 

 of sodium on carbonic acid. Seasoning from analogy, the author 

 supposed that hyposulphurous acid would be formed by the action 

 of sodium on sulphurous acid, a prevision which experiment con- 

 firmed. Dr. Dupre is thus led to regard hyposulphurous acid as 



* • Zeitschrift fur. Analyt. Chera.,' 1866, p. 279. 

 t Ibid., p. 285. 



