BUTTERFLY PAINTING. 23 



wholly vanished : its cleverest touches turned to coarse, 

 flspulsive daubs and stains. 



Now, bring the microscope's most searching powers 

 to bear upon the painting of an insect's wing, and w 

 find only pictures within pictures as the powers in- 

 crease ; the very pigments used turn out to be jewels, 

 not rough uncut stones, but cut and graven gems, bedded 

 in softest velvet. 



Ii by gentle rubbing with the finger-tip the scales 

 be removed from both sides of the wing (for each side 

 is scale-covered, though generally with a very different 

 pattern), there remains a transparent membrane like 

 that of a bee's or fly's wing, tight stretched between 

 stiif branching veins, but bearing no vestige of its late 

 ay painting, thus showing that the whole of the colour- 

 hg resides in the scales, the places occupied by the 

 roots of the latter being marked by rows of dots. 



Hitherto we have been looking at these scales as the 

 component parts of a picture, like the tesserae of mosaic 

 work ; but they are no less interesting as individual 

 objects, when viewed microscopically. To do this, deli- 

 cately rub off a little of the dust or scales with the 

 fciger; then take a slip of glass, and pressing the 

 finger with the adhering dust upon it, the latter will 

 lome off and remain on the glass, which is then to be 

 placed under the microscope. These scales may bv, 

 treated either as opaque or transparent objects, and in 

 both conditions display exceeding beauty, some of these 

 single atoms showing, by aid of the microscope, as 



