92 THE MICROSCOPE. June 



THE MICROSCOPE. 



New Series, 1893. 



For Naturalists^ Physicians, a?id Druggists, and Designed to Popularize 



Microscopy. 



Published monthly. Price Si. 00 per annum. Subscriptions should end 

 TP'th the year. The old series, consisting of 12 volumes {i88i-j8g2), ended 

 with December, i8g2. Sets of the old series cannot be furnished. All 

 correspondence, exchanges, afid books for fiotice should be addressed to the 

 Microscopical Publishing Co., Washington, D. C, U. S. A. 



CHARLES W. SMILEY, A. M., EDITOR. 



EDITORIAL. 



The Antwerp Exhibition. — The best exhibits of micro- 

 scopes are by EngUsh firms, notably W. Watson & Sons. They 

 show the Van Heurk microscopes which are admirable for scien- 

 tific research. The lenses are fine and all the parts adjustable 

 with ease and accuracy. They also show slips, mounts, etc., 

 as well as photographic apparatus. 



Aluminium. — Its weight is i that of iron, } that of silver, 

 \ that of gold. A gun metal casting weighing 53 pounds could 

 be cast in aluminium with only 16 pounds. It is very male- 

 able and can be rolled like gold or silver. It conducts heat and 

 electricity readily. It is not corroded by moisture, sulphur, 

 vinegar, or dilute acids. It is too soft to stand much wear or 

 strain. For use in microscopes it is alloyed with nickel, cop- 

 per, tin, silver, etc. The oldest aluminium works are only 35 

 years old. In nature, this metal is very widely distributed. 

 The aluminium bronzes are among the very best as they resist 

 oxidisation, are unafi'ected by sea water or by ammonia. 



A New Biological Microscope. — Messrs. Swift & Son have 

 made an instrument with the posterior limb of the tripod 

 doubled and rotating on a pivot. This gives increased steadi- 

 ness to the stand and the instrument can be packed in a 

 smaller case. The pivot has a strong spiral spring which pre- 

 vents it becoming loose and takes up any wear on the bearing 

 surfaces. 



