234? Intelligence and Miscellaneous Articles. 



decomposes it, and precipitates chloride of lead. Several analyses 

 yielded the formula PbCl, SPbO C 4 H* O 3 + 15HO. 



Iodide and Carbonate of Lead is prepared by digesting carbonate 

 of lead with iodide of lead until the excess of iodide of lead has 

 dissolved. This salt is yellow and insoluble in water. Its formula 

 is Pbl, PbO, CO'K—Comptes Rendus, p. 1 180. 



ON THE VOLATILE ACIDS OF CHEESE. BY MM. ILJENKO AND 

 LASKOWSKI. 



The authors cut fifty pounds of Limbourg cheese, which possessed 

 a very strong odour, into small pieces, mixed them with water, and 

 submitted the mixture to distillation in a large alembic, water being 

 occasionally added during several days. By this operation a some- 

 what turbid ammoniacal liquor was obtained, which was supersatu- 

 rated with sulphuric acid and again distilled. The product was after- 

 wards saturated with barytes water ; the salt obtained was evapo- 

 rated to its crystallizing point ; the acid was again separated and 

 converted into a salt of silver. Analysis showed that this volatile 

 acid was entirely valerianic acid. 



The residue was afterwards saponified by means of potash, the 

 soap decomposed by potash, and subjected to a fresh distillation, 

 and there was thus obtained an acid liquid which was saturated with 

 barytes and evaporated to crystallize ; it yielded a mixture of seve- 

 ral salts of barytes, which were separated by means of their different 

 solubility in water. The rough salt was mixed with seven parts of 

 water and heated to boiling ; the caproate of barytes dissolved, and 

 afterwards separated in crystalline tufts of considerable size, whilst 

 the butyrate remained in solution ; this was converted into a salt of 

 silver and analysed. 



The barytic salts, which were not dissolved by the seven parts of 

 boiling water, were composed of caproate and caprylate of barytes ; 

 and they also were separated by their different solubility. 



It appears then that cheese contains the following volatile acids : 



Butyric acid C 4 H 8 O 2 



Valerianic acid. . C 5 H 10 O 2 



Caproic acid. . . . C 6 H 12 2 . 



Caprylic acid . . C 8 H 16 O 2 



Capric acid C 20 H°-° O 2 



Valerianic acid occurs in the largest quantity, and its presence 

 had been previously discovered by M. Balard in the cheese of Ro- 

 quefort. All these acids, it will be observed, are homologous sub- 

 stances. 



The authors also performed some experiments on the fused por- 

 tion of cheese ; they obtained by means of boiling alcohol perfectly 

 crystalline margarine from it; it was fusible at 127° Fahr., and 

 margaric acid was obtained from it. The rough margarine was mixed 

 with some liquid glycerine. Unaltered caseine was also present, so- 

 luble in boiling water and insoluble in alcohol. There was also pre- 



