ELEMENTARY PHOTO-MICROGRAPHY. 79 



The whalebone section, for instance, photographed 

 by red light gives perfectly satisfactory results 

 showing ample detail in structure." 



As a general guide, when contrast is required 

 use for stained preparations niters as under : 

 For blue use a red filter. 



green red 



,, red green 



,, yellow blue 



brown ,, blue 



purple green 



,, violet yellow 



LIST OF WRATTEN " M " FILTERS. 

 Name of Filter. Visual Colour. 



A Scarlet 



B . . . . . . Green 



C . . . . . . Blue-violet 



D Purple 



E . . . . . . Orange 



F Pure red 



G . . . . . . Strong yellow 



H Blue 



K3 Bright yellow 



By using these screens together, the spectrum can 

 be divided up into monochromatic portions, thus : 

 Name of Filter. Visual Colour. 



A and D . . . . Deep red 

 A and B Brown 



