,
the "gossan" of our lodes, and that though the gold was deposited,
this occurred in an irregular way, and it was coated with a dark brown
powdery film something like the "black gold," often found in drifts
containing much ferruginous matter. Such were the curious Victorian
nuggets Spondulix and Lothair.

Professor Newbery also made a number of similar experiments, and arrived
at like results. He states as follows: "I placed a cube of galena in
a solution of chloride of gold, with free access of air, and put in
organic matter; gold was deposited as usual, in a bright metallic film,
apparently completely coating the cube. After a few months the film
burst along the edges of the cube, and remained in that state with
the cracks open without any further alteration in size or form being
apparent. Upon removing it a few days ago and breaking it open, I found
that a large portion of the galena had been decomposed, forming chloride
and sulphate of lead and free sulphur, which were mixed together,
encasing a small nucleus of undecomposed sulphate of lead. The formation
of these salts had exerted sufficient force to burst open the gold
coating, which upon the outside had the mammillary form noticed by
Wilkinson, while the inside was rough and irregular with crystals
forcing their way into the lead salts. Had this action continued
undisturbed, the result would have been a nugget with a nucleus of
lead salts, or if there had been a current to remove the results of
decomposition, a nugget without a nucleus of foreign matter."

But Newbery also made another discovery which still further establishes
the probability of the accretionary growth of gold in drifts. In the
first experiments both investigators used organic substances as the
reagent to cause the deposit of gold on its base, and in each case these
substances whether woodchips, leather, or even dead flies, were found
to be so absolutely impregnated with gold as to leave a golden skeleton
when afterwards burned. Timber found in the Ballarat deep leads has been
proved to be similarly impregnated.

Newbery found that gold could also be deposited on sulphurets without
any other reagent. He says: "In our mineral sulphurets, however, we
have agents which are not only capable of reducing gold and silver from
solution, but besides are capable of locating them when so reduced in
coherent and bulky masses. Thus the aggregation of the nuggety forms of
gold from solution becomes a stil