582 Transactions. — Chemistry. 



(2.) Gold, also platinum, oxidized or sulphurised until they 

 will not amalgamate in clean mercury, can be substituted for 

 copper in the above experiment with similar results. 



(3.) Silver, also copper iodized until of a pale-yellow or 

 whitish aspect, can be substituted for copper in experiments, 

 with the same results. 



(4.) A smooth dry platinum wire plunged in melted bees- 

 wax, sealing-wax, or guttapercha, and dipped in again and 

 again until the coating acquired is to be easily seen over its 

 entire surface, can also complete the interpolar connection on 

 dipping its free ends into mercury poles. 



The conductivity of certain thin films for electricity ex- 

 plains, as I think, the very contradictory statements that have 

 been made respecting the capacity or the incapacity of 

 argentic sulphide to conduct electricity. Long ago Professor 

 Faradayplaced this compound among the electric conductors ; 

 but that it really does class as such has been disputed, and 

 still is, I believe, disputed. In 1876''' I showed, and, as I 

 think, very clearly, that Faraday's statement is correct. 

 Now, I used very thin films of this sulphide in the experiment 

 I made for settling the point in question, and I suppose that 

 those experimentalists who get different results from those of 

 Faraday used the sulphide in a massive form, and gave con- 

 tact by only a very small extent of surface. If this surmise 

 of mine is correct the whole matter in dispute is at once 

 explained, and it must be allowed that this compound 

 (argentic sulphide) is an electric conductor, but a feeble one. 



Art. LXI. — On the Oxidation of Mercury in Air and Water, 

 also of Iron, in Alkaline Solution. 



By William Skey, Analyst to the Department of Mines. 



[Bead before the Wellington Philosophical Society, 17th February, 1897.] 



The Oxidation of Mercury. 

 About twenty years ago I stated before this Society! that, for 

 certain reasons I at that time gave, the metal mercury 

 should, like gold and platinum, oxidize in air and water 

 conjointly, and I have now, as I believe, succeeded in prov- 

 ing that mercury does oxidize under these circumstances. 



The following is a short statement of the results upon 

 which I base this conclusion : — 



* Trans. N.Z. Inst., vol. viii., p. 345. 

 t Trans. N.Z. Inst., vol. viii., p. 342. 



