126 ON THE FOEMATION Or MOSS GOLD AIID SILYEE. 



out the oxide of iron and to examine tlie residual gold for 

 crystals or any trace of crystalline structure whicli might be 

 present, as I hoped by the above means to set the gold so 

 completely free from the matrix that I could at once ascertain 

 whether it existed in the mispickel in a crystallized form or 

 only in irregular or amorphous lumps and particles. 



On taking the specimen out of the muffle after the whole of 

 the arsenic and sulphur had been driven off, I found that the 

 surface was studded mth small, irregular, more or less rounded 

 excrescences of gold, having much the appearance and colour of 

 small drops of sulphur. On closer examination, and especially with 

 the aid of the microscope, the surfaces of these mushroom-like 

 growths were seen tO be covered with minute capillary wires 

 and branching forms, which in some cases appeared to be made 

 up of minute irregularly-formed crystals. This is more noticeable 

 in the second specimen. Some of the cavities in the gold are seen 

 to be lined with the most beautiful little spiculse of gold, and 

 some of the rounded bosses are composed solely of such spiculse, 

 interlaced into a ball-like form. Many of these capillary wires 

 are curled into most symmetrical and beautiful spirals ; one about 

 ^ to i inch in length and of about ^^ inch in diameter is coiled 

 with the utmost regularity, the pitch of the screw being main- 

 tained uniform throughout its entire length. 



In some cases the mushroom-like growths are seen to be 

 supported on but a very slender stem, while others have 

 apparently become recumbent from their weight and have grown 

 along the surface. 



It is by no means an uncommon thing to find natural gold in the 

 form of capillary threads, which are often interlaced and twisted 

 into beautiful and fantastic shapes ; also as thin flakes and scales^ 

 having a more or less fibrous surface ; and at times in scales 

 so exceedingly thin that they are not thicker than ordinary gold- 

 leaf. Some of the gold from Oura, near "Wagga Wagga, occurs 

 in this manner. The best known xiustralian locality for filiform 

 gold is, perhaps, the Upper Cape Eiver, Queensland. 



I should mention, however, that I have never seen or iieard of 

 any native gold presenting exactly the same kind of appearance 

 as the before-described artificially -formed specimens, but certainly 

 the latter is at times somewhat similar. 



Origin of the Moss Gold. 



The general appearance of these peculiar cauliflower-like 

 excrescences of gold would at first sight tend to give one the 

 impression that they had been formed in somewhat the same way 

 as the blebs and excrescences often observed on coke, whicli are 

 so familiar to us in a fire made of so-called bituminous coal — i.e., 

 caking coal, in whicli constantly we see portions of the coal fuse 



