80 THE ROYAL SOCIETY OF CANADA 



The stereographs were then made by the author's rocking stage 

 described in the Royal Microscopical Society's Journal for November, 

 1901. 



The ^VTiter recently thought of applying this same process of 

 making stereographs for examining anatomical microscopic preparations 

 such as bone sections, vegetable tissue, as pitted tissue in coniferous 

 woods, stellate cells in the water lily, crystals, etc., and then these latter 

 as seen by plane polarized light, and lastly in colours by autochrome 

 plate and with a selenite plate, such as cotton and linen fibre, crystals 

 and blood globules. 



The author desires to acknowledge with thanks his indebtedness 

 to the kind assistance of his daughter, Miss Girdwood, and his friends 

 Mr. Bryce Scott of Moncton, and Mr. Malone of Antigua, and without 

 whose assistance the beautiful pictures shown the author himself could 

 not have made in consequence of his loss of sight. 



In the course of the making of these microstereographs some 

 improvements in the original rocking stage were found necessary; it 

 was requisite to have the knife edges of the stage in line with the optical 

 axis of the microscope, to have the rocking stage pressed up against 

 the knife edges quite tight so as to have no slack. This was done by 

 putting a piece of soft vulcanized rubber under the rocking stage, to 

 have it screwed firmly to the main stage of the microscope by two small 

 screws underneath. When using the higher power, such as the 6th 

 and the 12th oil immersion, it was found that the angle of the lens 

 was so narrow that it was not possible to get a sufficiently large angle 

 of rocking, namely, 7-5 degrees each way. With my 6th with which 

 the red blood corpuscles were made, we had to be content with only 

 6 degrees altogether. Still they are stereoscopic and show the cup- 

 shape. With the 12th oil immersion still less rocking is available 

 but it is hoped to rectify this by another means not yet tried out. 



