Skey. — On Occurrence of Native Lead ivith Gold. 367 



tion of those of Becquerel. Thus, his crystals form a series of 

 narrow fissures or spaces between them and the bottom of the 

 vessel in which they are placed, also a further series with the 

 crust of cupric sulphide which forms around them, and in 

 these spaces metallic copper is deposited by the same cause 

 as that operating in Becquerel's cell. 



On repeating Loew's experiments I have always found that 

 the copper is deposited in a solid film on the containing vessel, 

 and in nuggets equally coherent, proving that a concentration 

 of the metal takes place. Each sepai'ate deposit of copper 

 undoubtedly performs the part of the negative pole of a gal- 

 vanic battery, this polar condition being due to the fact that 

 they are preserved from the attack of the sulphide by cupric 

 sulphate and cupric sulphide, with which they are surrounded. 

 Under these circumstances electric currents must be produced, 

 and without these to concentrate and locate the deposits the 

 copper could not be so compact and aggregated. 



Chemical decomposition alone, with its constant concomi- 

 tant electricity, is certainly competent to produce all the 

 phenomena that Becquerel and Loew have discovered. There 

 is therefore no need, in order to explain the deposition of 

 copper in a fissured cell, to assume that either capillarity or 

 osmose intensifies the current of electricity. 



I will only add that I have all along strictly confined my- 

 self to a discussion of the theories of Becquerel and Loew as 

 applied to explaining the deposition of metals and metallic 

 compounds in narrow fissures or minute pores ; but if my 

 criticisms and theory are correct, the idea of electro-capillarity 

 as a compound force present in vegetable and animal 

 organisms will also have to be given up. Here, as in Bec- 

 querel's cell, the only use of the capillary space or fissure is to 

 preserve for a time that which chemical or electrical forces 

 have produced, and this simply by the mechanical limitation 

 wiiich it sets upon their operations in the organisms which I 

 have named. 



Aet. XLVII. — 071 the Occurrence of Native Lead at Calling- 

 wood, and its Association with Gold. 



By William Skey, Analyst to the Geological Survey. 



[Bead before the Wellington Philosophical Society, 3rd October, 1SS8.] 



(Abstract.) 



A NUMBER of small rounded pieces of a soft malleable substance 

 were forwarded to the Geological Survey Department by Mr. 

 Washbourne, as lead, covered with the carbonate, and upon 



