ON MICKOSCOPICAL DRAWING AND PAINTING. 173 



crushed, they shew the impossibility of revealing 

 the correlation, or association of parts, by mere 

 transmitted light or in any way, except (may it be 

 said) by artistic discernment. The head, and sur- 

 rounding parts of an insect, prepared in this way, 

 with pure light from beneath and above, discloses a 

 combination of form and colour of surpassing 

 beauty; the blaze from the speculum sweeps over 

 the opaque parts with reflections revealing the most 

 exquisite tints, while the paraboloid shows, in actual 

 perspective, the parts beneath in all their natural 

 colour, and bathed in refulgence. An opaque 

 polypodom, touched by such reflections, while the 

 extended polyps are illuminated from below, is 

 another instance, amongst many, of beauty, exalted 

 by light. 



For purely opaque objects, the only good light is 

 from the speculum, by no other means can the 

 finest effects of colour and shadow be obtained. It 

 should be fitted to tho stand of the instrument, not 

 to the stage, nor should it slip on the front of the 

 objective. On the stand it can be moved without 

 disturbing the object or the focus. The old fashioned 

 Lieberkuhn cannot be used ; it requires an object 

 to be prepared in a particular way, and as an 

 illuminator is palpably defective; the light com- 

 pletely surrounds and enwraps the object ; brilliancy 

 is present, but no contrasts. In using reflectors, 

 the lamp should be placed close to the level of the 

 stage, within easy reach of condenser and speculum. 



In painting purely opaque objects under top light 

 the treatment of background deserves attention ; eggs 

 of insects or parasites are generally attached to frag- 

 ments of wood, leaves, cuticles, hair or feathers, it 



