Page:Proceedings of the Royal Society of London Vol 60.djvu/33

Rh Q.0l d .................. 27‘914 kilograms. Silver................ 3‘568 „

which proved that the actual gold standard of the ingot was 703-9.

The base metal in two similar ingots was found by analysis to be composed as follows: (492) (494.) Silver......................... 8*9 8-0 L e a d ......................... 9‘0 77 Zinc ......................... 4-8 8-5 Copper..................... 3'2 Iron ......................... 0‘4 l-'(3 Nickel ...................... 0-8 1*8 Gold (by difference).. 70*9 69'2 100-0 100-0

from which it would appear that the presence of one or both of the metals—zinc and lead—bears in some degree upon these variations in quality—it being well known that gold will alloy, and be constant in quality, with either silver or copper or with both in almost any proportions.

Advancing progressively, I now cite an instance of irregular distribution in a much baser alloy of gold.

An ingot of base gold alloy (P. 13) weighing 9’570 kilograms.

Determinations from the top of this ingot gave results:— Point a— Gold. Silver. 265-0 — 378-4 213 383-0 — Prom the bottom, point b— 527-2 — 560-0 66 545-5 —

Prom a “ dip ” taken from the fused alloy— 561-0 — 618-5 75 683-0 — differences which are too significant to need comment