1901} MICROSCOPICAL JOURNAL. 257 
the eyepiece, it can be used at any angle from the verti- 
cal to 45 degrees, The image from the eyepiece is re- 
ceived upon the mirror which consists of a silvered disc 
of microscope cover-glass mounted on a brass plate, which 
can be revolved by the pin. The image is then reflected 
to the neutral tint glass which revolves on the pin and 
the same effect is produced as in the Beale’s pattern, ex- 
cepting that there is no reversal of the sides. 
I can strongly recommend the trial of this little device. 
Much of the failure in drawing with camera lucidas is 
due to the attempt to use eyepieces of too high power. 
It will be invariably found that an eyepiece magnifying ~ 
six diameters or even less is the most satisfactory, and 
this equally applies to Ashe’s Camera Lucida. 
CoLoRR-PHOTO-MICROGRAPHY.—It has often been de- 
plored that although very exquisite reproductions of 
delicate structure can be made by photo-micrography, no 
satisfactory means have been available for reproducing 
exquisite colour tints, which make the vision of numer- 
ous objects through the microscope so entrancing. At- 
tempts have been made, and not without a marked degree 
of success, by means of the tricolour process of Ives and 
others, but it called for a high degree of technical skill, 
and a vast amount of patience, experiment, and time. 
The Sanger Shepherd process of natural colour photo- 
graphy overcomes the majority of the difficulties which 
prevented workers from embarking on attempts in this 
direction. It is true that the results cannot be printed 
on paper, but must be viewed as transparencies ; but they 
admit of ready exhibition through a projection lantern, 
and for direct examination can be held or supported to- 
wards a suitable white backing. 
The great advantage of it is that no alteration has tu 
be made to the ordinary camera. The recommended 
adaptation to the camera consists of a repeating back to 
earry three plates. Immediately in front of these plate- 
