T50 



thp: guide to nature 



A CORNER IX THE MAIN LABORATORY. 



It therefore seemed of interest to 

 subject the surface of the metal before 

 and after immersion to microscopical 

 examination. 



The results of such observation were 

 more than g-ratifvinQ- as the accom- 



Danying- photomicrographs will show. 

 The appearance of a piece of freshly 

 cast cadmium, polished and etched in 

 nic.ic acid, is shown in Fig. i, the mag- 

 nification being two hundred diameters. 

 After five weeks immersion in a solu- 



AIAIN LAliORATORV SHOWING VIBRATION-FREE SUPPORTS. 



