426 MM. Svanberg and Struve on the Atomic Weight 

 The crystalline salt is accordingly composed of — 



Found. 

 a. Calc. b. Calc. I. II. 



1 at. Soda 389-729 10-139 389-722 10-244 10552 



3 at. Molybdic acid 2666-966 69-378 2627-487 69-061 69-173 



7 at. Water 787-353 20483 787-353 20-695 20-275 20350 



3844-048 100000 3804-569 100-000 100-000 



and the anhydrous salt of — 



a. Calc. b. Calc. Found. 



1 at. Soda 389-729 12-747 389729 12917 13235 



3 at. Molybdic acid 2666966 87-253 2627487 87-083 86-765 



3056-695 100-000 3017216 100-000 100-000 



Reduction of the Trimolybdate of Soda by Hydrogen. — Wbh- 

 ler first observed and described the peculiar behaviour of the 

 bitungstate of soda towards hydrogen, it became therefore 

 interesting to ascertain how this salt of molybdic acid would 

 behave under the same treatment. With the tungstate, a 

 curious compound of oxide of tungstenium and soda was 

 formed by the reduction; no such thing however happens in 

 this case. The molybdate of soda behaves precisely like the 

 corresponding potash salt. 



0*6534 grm. of fused trimolybdate of soda lost on reduction 

 0*043 grm., and the residue yielded on exhaustion with water, 

 evaporation, ignition and weighing, 0*266 grm. neutral molyb- 

 date of soda. 



100 parts of the anhydrous trimolybdate of soda conse- 

 quently afford — 



6*581 oxygen 

 40*710 neutral molybdate of soda, and 

 52*709 insoluble oxide (estimated by the loss). 



On comparing these values with theory, we find that 



1 at. NaO, MoO> + 2HO is f J £ ggflK^ and 



decomposed into ] « ttq 



which gives in 100 parts — 



a. b. 



Oxygen . . 6-565 6*625 



NaO, MoO 3 41*823 41*393 



MoO, MoO 3 51*612 51*981 



100*000 100000 



The amount of neutral molybdate of soda obtained does 

 not agree accurately with the quantity required by theory, but 

 this is owing to the glass being very much acted upon by the 

 neutral salt in the operation. In this experiment the reduc- 

 tion was continued for some hours uninterruptedly, the entire 

 mass being kept at a red heat in order to ascertain whether 



