Roberts -dutsten 8f Rose.. 



Roy. Soc. Proc., Vol. 07, PI, I 



Fig. I. Surface of an Ingot of Standard 

 Gold, (unetched) -\4. 51). 



Fig. 3. Eutectic, (80 per cent Gold, 

 20 per cent Copper) x 15800. 



Fig. 2. Standard Gold. 



Fig. 4. Standard Gold, x 15800. 



5- 27 per cent Gold, 73 per 

 cent Copper* X4-5D 



Fig. 6. Eutectic portion of 27 per cent 

 Gold, 73 per cent Copper, x 63200 



