]12 



On the Improvement of Nachet's Stereo-pseudoscopic 

 Binocular Microscope. By Charles Heisch, F.C.S., 

 F.R.M.S., &c. 



(Read May 13th, 1S6S.) 



At the conclusion of last session Dr. Carpenter brought 

 before the Society Nachet's Stereoscopic and Pseudoscopic 

 Microscope, pointing out its advantages and disadvantages. 

 It struck me that by slightly modifying its construction the 

 disadvantages might be removed, and that it might thus be 

 made to combine to a great extent the advantages of both 

 the Nachet and the Wenham form of instrument. A re- 



ference to the subjoined iigure, which represents the essential 

 parts of Nachet's instrument, will show the defects to be 

 overcome, a, b is the posterior of the objective, c, d, e, f 

 a piece of thick parallel glass, ground at one end to an angle 



