Chemical Science, 233 



Dumas. — Tliis table gives the specific p^ravity of vapours and gases, 

 as compared to air, and also the density, as calculated from the 

 weights of their elements, and from certain experiments. There is 

 likewise in the table a column indicating the weight of a litre of 

 each gas, or vapour, at the temperature of 32^ F., and barometric 

 pressure of 29.92 inches, the weight being expressed in grammes. 



Observed. Calculated. Weight. 



Iodine 8.716 8.6118 11.3230 



Mercury 6.976 6.9783 9.0625 



Proto-chloride of phosphorus 4.875 4.8076 6.3532 



Arsenuretted hydrogen 2.695 2.6950 3.5023 



Proto-chloride of arsenic .... 6.3006 6.2969 8.1852 



Chloride of silicium 5.939 5.9599 7.7154 



Fluo-silicic acid 3 . 600 3 . 5973 



Chloride of boron 3.942 4.0793 5.1212 



Fluo-boric acid 2.3124 2.3075 



Per-chlorideoftin 9.1997 8.9930 11.9514 



Per-chloride of titanium 6.856 7.0470 8.881 



Phosphorus 2.2052 



Arsenic 5.1839 



Silicium 1.0197 



Boron 0.7487 



Tin 4.0530 



Titanium 2 . 1070 



Annates de Chimie^wxuu 39 1. 



The litre is equal to 61.02525 cubic inches ; the gramme to 15.44 



grains. 



10. Oji the Existence and Nature of Bromine. — Professor Liebig 

 has repeated the experiments of M. Balard, relative to the produc- 

 tion of this peculiar body upon the mother waters of the salt-works 

 of Theodorshalle, near Kreutznach, and has obtained as much as 

 20 grammes (308.8 grains) of bromine from 30 pounds of the fluid. 

 The process adopted was that of M. Balard. After repeating most 

 of the experiments of M. Balard, with consistent and satisfactory 

 results, M. Liebeg proceeded to some which he considers as sup- 

 porting the simple view of the nature of the substance. Iron was 

 heated to redness in a glass tube, and the vapour of bromine dried 

 by chloride of calcium, passed over it; on coming into contact 

 with the metal, the latter became incandescent, without any dis- 

 engagement of gaseous matter ; the mass fused into a body of a 

 clear yellow colour, having, when cold, a lamellar structure, and 

 dissolving readily in water. It was proto-bromide of iron, and 

 yielded bromine on the action of chlorine. Platina and lamp-black 

 did not act on the vapours of bromine : 2.521 parts of the bromide 

 of potassium being decomposed by nitrate of silver, gave 4.041 

 parts of bromide of silver, which, by calculation, gives 94.11 as the 

 atom of bromine oxygen being 10. — Annates de Chimiey xxxiii. 331, 



Royal Academy of Sciences at Paris, Oct, 2, — M. Cbevruel 



