Skey. — 071 Cyanogen. 575 



radical at all comparing with the elements here named. 

 This theory, when circulated in England, did not meet with 

 any favour, not that the facts 1 adduced in support of it 

 were at all questioned, but that others were put forward 

 which, as was stated, conflicted with them. Not then having 

 any further facts to adduce I let the subject drop ; but just 

 recently, owing to the question assuming considerable import- 

 ance, I took it up again, and I have, as a result, discovered 

 further evidence, which, as I believe, is greatly in favour of my 

 theory, and which I adduce. I, therefore, state this evidence, 

 which is to the effect that cyanogen does not, as it is at pre- 

 sent supposed, dissolve either silver or gold when adminis- 

 tered to it as an aqueous solution, whether these are dilute or 

 concentrated — that, indeed, as far as I have at present in- 

 vestigated the matter, cyanogen does not even attack either 

 of these metals at all. 



The exhibits 1 and 2 on the table here show a little silver 

 and gold leaf that have been in a strong solution (aqueous) of 

 this gas for five days, and, for comparison, pieces of silver and 

 gold leaf, from the same sheets respectively, that have not 

 been in the solution. I do not think any one can discern any 

 difference in the appearance of these — that is, any loss of 

 either the gold or silver leaf that has been in the cyanogen ; 

 and I think that you will allow that this is -a very severe test 

 in the case of gold, when you consider that its thickness is 

 not more than ^-^r—^in. To get a still more crucial test I 

 have coupled gold leaf with clialcopyrites in the solution of 

 cyanogen (as you may see in the exhibit No. 3), so as to have 

 the benefit, the stimulating effect, that we get by allowing any 

 electricity produced by chemical action to become current 

 electricity. Still, you may see the result is the same ; the 

 gold remains, as far as we can see, absohctcly miaffected. 



In all these experiments I feebly acidulate the cyanogen 

 solution to counteract the decomposing efi'ect produced by 

 atmospheric ammonia or the alkali of the vessels that I use. 

 Thus I completely avoid the production of gold-dissolvers — 

 that is, the alkaline cyanides which otherwise would interfere 

 with the accuracy of investigations of this nature. 



Light does not appear to act on these solutions of cyanogen, 

 at least so as to produce any solvent for gold, such as ammo- 

 nium-cyanide. 



I, then, assert that cyanogen gas, like oxygen, is far more 

 soluble in water than in saline solutions generally that have 

 no chemical effect on it, but that, as it now appears to me that 

 this is a general character of gases, I do not count upon this 

 fact to aid me in my contention. I, then, go on to state, in 

 regard to the position of this compound radical among the 

 elementary radicals, that wherever this is, it cannot be with the 



