145 
On Colour-Illumination . By J. Rlieinberg. 
sidering the attention given to the aplanatism of condensers. Surely 
the one demands the other. 
“I have, in conclusion, only to add that we are indebted to 
Messrs. W. Watson and Sons and R. and J. Beck, Ltd., for the loan 
of the Microscopes displayed this evening, whilst a number of the 
slides are from the collection of the Society. 
“To most of the cards at the sides of the Microscopes, a colour- 
disc is attached, exactly the same as the one employed in the instru- 
ment; and by holding the cards against the light, the colours can he 
examined.” 
Fig. 29. 
A, Colour illuminator, with Abbe 1*4 N.A. condenser, seen from top, showing one 
carrier, c, pulled out ; p, pointer of iris diaphragm; s, projecting part of a special 
carrier B, which can be pulled out altogether, and any kind of stop inserted as 
required. 
C, One of the metal carriers, top view ; s, screws for affixing little metal plate or 
coloured piece of gelatin, indicating kind of stop. 
D, Cross section of metal carrier. 
E, One of the sheets of celluloid separating the carriers. 
Stops on left-hand side. 
1. Matt ground celluloid spot. 
2. Black central spot. 
3. Blue „ „ 
4. Bed 
5. Green „ „ 
6. Red spot, green periphery (composi- 
tion method illumination). 
7. Large red spot, green periphery, 
(composition method illumination). 
8. Black and white quarters. 
Stops on right-hand side. 
1. Black annulus, 5-15 mm. diameter. 
2. „ „ 10-20 mm. „ 
3. Blue periphery, clear centre. 
4. Red „ „ „ 
5. Green „ ,, „ 
6. Yellow „ „ „ 
7. Red and green halves, clear centre. 
8. Blue and red quarters „ „ 
9. Adjustable oblique light stop. 
10. Adjustable slot. 
9. Clear annulus in black stop. 
10. Malachite green screen. 
N.B. — For low-power colour illumination the top lens of condenser must be 
removed. 
