W. Skey. — On the Analogy of Cyanogen to Oxygen. 383 



also a compound body. I need not remind you in this connection that any 

 theory which touches upon the nature of this gas has now an especial interest 

 to us, for as you will be aware this and our most common gases or gaseous 

 vapours are, for good reasons, considered to be distributed throughout the 

 earths and suns generally,* and even to pervade the spaces between them 

 and to perform all the functions we have hitherto allotted to a purely hypo- 

 thetical substance. The nature therefore of any gas which is possibly a 

 constituent of that which we now consider to be a universal atmosphere, 

 becomes invested with an importance to us far beyond what we could even 

 conceive of a short time since. 



Lastly, in regard to the question as to the nature of our elements, it 

 appears a very noteworthy circumstance that, by combining cyanogen with 

 sulphur, which is also an analogue of oxygen, we obtain a compound analogous 

 to the halogens I have referred to. That this ternary compound sulphocyano- 

 gen should be thus a true salt-radical, is strongly favourable to the idea that 

 one or more of the chlorine group of elements is of a compound nature, and in 

 relation to this it is worthy of record that, as I have already pointed out, the 

 " equivalent number of sulphycyanogen is one which is very nearly the mean 

 between that of chlorine and bromine." 



However, whether these facts indicate anything of this kind or not, I 

 think the object of this paper has been fulfilled, for I believe I have 

 shown that, to use a familiar but significant phrase, cyanogen has not the 

 " stuff" in it for making a salt-radical singlehanded, therefore it is not in any 

 way analogous to one, but in order to make it so we must combine it 

 with another element, so that three elements in place of two are as yet the 

 smallest number required to form a compound salt-radical. 



In concluding my paper, I cannot avoid expressing a wish that the question 

 which I have raised here had been taken up by some one more accustomed, by 

 training and association, than myself, to grapple it by the aid of what is well 

 termed the "New Chemistry." I have worked at this question by the old 



any 



will 



Fuel of the Sun, by W. Mattieu Williams, F. C. S. 





