20 PROCEEDINGS OF THE AMERICAN ACADEMY 



has been made to formulate the remarkable compounds of tungsten 

 described by Wohler and others, and which may be expressed empiri- 

 cally by the formulas 



W 3 (J Na 2 , and W 5 O u Na 2 . 



If we double these formulas, we may bring them into harmony with 

 the series of acid tungstates by writing them respectively, 



wo a = wo 2 



I I 



Na - O - W0 2 — W0 2 - O - Na 



i i 



o o 



I I 



N a _ O - W0 2 = W0 2 - O - Na, 



and 



W0 2 = W0 2 



II II 



wo 2 — wo 2 



II II 



wo 2 — wo 3 



I I 



o o 



I I 



Na - O - W0 2 — W0 2 - O - Na 



i i 







1 I 



Na - - W0 2 — W0 2 - O - Na. 



These formulas, if like the others purely hypothetical, have at least 

 the merit of explaining the production of the insoluble sodium salts 

 in a simple and natural manner. They are also entirely consistent 

 with the simplest view which we can adopt with respect to the consti- 

 tution of the blue oxide of tungsten, which is commonly written 

 W 2 O i , but which is much more probably W 4 O 10 , and structurally 



WO, — wo 2 



o 



1 I 

 wo 2 — wo,. 



The progress of science tends to show that the constitution of inor- 

 ganic compounds is more complex than would at first appear. It 

 would not be difficult to multiply instances which support this view, 



