22 



Transactions of the Society. 



IV. — A Simple Method of Illuminating Opaque Objects. 

 By J. E. Stead, F.R.S. 



(Bead December 16, 1908.) 



The main difficulty in illuminating opaque objects, where the 

 illuminant is independent of the Microscope, is in making the 

 adjustments so as to obtain maximum illumination. By the use of 

 the illuminating device described below, this objection is quite 

 overcome. 



The illustrations (figs. 3 and 4) show with clearness the simple 

 system in which the illuminating source and the reflectors are 

 attached to the object-glasses. 



In the arrangement shown in fig. 3 — suitable for 1^ objectives 

 — the cover-glass reflector is placed between the nose of the glass 

 itself and the object, and is supported in position on a right-angle 

 tube, one limb of which is attached to the object-glass; into the 



Fig. 3. 



Fig. 4. 



other is fixed a small electric lamp, which can be switched on when 

 the Microscope is in use. 



Fig. 5 is an improvement of fig. 3, and is so arranged that 

 either vertical or oblique rays of light can be thrown on the 

 sections. This is effected by a device in which the tube carrying 

 the lamp and reflector can be moved to the right or left, in such a 

 way that when in one position vertical rays fall on the object, 

 and when in the other position, oblique rays. 



The illustrations are sufficiently clear to show this. 



When applied to ordinary Microscopes there is no necessity to 

 keep the Microscope in any one position when the operator is at 

 work, and it can be tilted to any angle without the slightest dis- 

 advantage. 



