PN THi: FOEMATIOK OF MOSS GOLD AND SILVER, 127 



and swell up into fantastic blebs and bladders until the impri- 

 soned gas breaks tlirougb the thin skin and inflames with a bril- 

 liant light. After the more combustible portions have been 

 volatilized and consumed, a hard, clinkery, and more or less 

 cauliflower-like excrescence is left. 



But I do not think that we can account for the form of these 

 cauliflower masses of gold in a similar way, for the mispickel 

 shows no traces of having undergone fusion, neither does the 

 gold ; the crystals of mispickel, which by the operation of roasting 

 hptve become converted into oxide of iron, still retain their 

 original form, even down to the jagged points along the sharp 

 splintery edges of fractured surfaces. Hence it cannot be urged 

 that the gold had merely been left in the form assumed by the fused 

 mispickel in the same way .that a cauliflower mass or capillary 

 thread of coke is left by the escaping gas from a piece of fused 

 coal. 



Neither can the gold have been merely squeezed out through 

 pores in the matrix by mechanical pressure in the same way that 

 clay is forced through moulds in the manufacture of earthenware 

 drainage pipes, for the enclosing matrix of mispickel during the 

 operation of roasting becomes comparatively soft and tender. 

 Hence it could not well offer sufficient resistance to the expansion 

 of the gold to act as a wire draw plate, even if we suppose that 

 the gold existed in the form of small pockets of metal, and that 

 there are the necessary minute apertures and perforations in the 

 mispickel through w^hich the expanding gold could make its 

 escape. 



And again, the forms exhibited by the gold show that it has not 

 been in a fused condition, neither does it appear even to have 

 l^een of a pasty consistency. 



To ascertain whether this remarkable form of gold was fur- 

 nished by artificial mixtures of the metal and mispickel, or was 

 solely confined to those occurring in nature, a series of experi- 

 ments was commenced, and the results obtained satisfactorily 

 showed that the same phenomena were presented by certain of 

 the artificial mixtures employed. 



Eocperiment. — 80 grammes of powdered mispickel were fused 

 under a film of borax v/ith one gramme of precipitated gold. The 

 whole of the gold was apparently taken up by the mispickel, for no 

 metallic particles or shot could be detected in the fused mass of 

 regulus. The button of regulus was then roasted at a low red 

 beat in the muflle ; it fused, but after the whole of the arsenic 

 and sulphur had been driven off, the oxide of iron was found to 

 be more or less covered with a brown, non-metallic looking cauli- 

 flower-shaped mass of gold. On scraping it with the point of a 

 knife the unmistakeable yellow metallic streak of gold' was at 

 once exhibited. 



