We have lately made several compounds of the halide acids and mixed 

 ethers. They unite in the proportion of 1 «l. 



We see here the effect of temperature on the valency of oxygen. 

 As the temperature decreases the valency increases, changing from four 

 to perhaps twelve. Similar results would be obtained, we believe, 

 were analogous compounds of sulphur, tellurium and selenium inves- 

 tigated. 



Valency of Nitrogen. 



We have measured the conductivity of nitrogen compounds in the 

 hydrogen halides and find invariably a decrease of molecular con- 

 ductivity with dilution. This points to the formation of compounds 

 in solution, and since in the case of triethyl ammonium chloride our 

 compound contains saturated (pentad) nitrogen, we believe that the 

 nitrogen takes on a valency higher than five. We have made no effort 

 to isolate these compounds. 



Hydrocyanic acid, the various nitriles and sulphocyanides conduct 

 well in the halogen aoids, and so, doubtless, do the isocya nicies. A 

 careful study of the conductivities of these bodies is to be desired, since 

 it might throw light on the oft-discussed question of their constitutions. 



