Royal Microscopical Society. 265 



the pigment seems due, and should be referred. It is a point for 

 further investigation and quite open to inquiry.* 



It seemed to me some attemjot might be made on a large scale 

 to ascertain whether if two artificial arrangements based on the 

 figures given of the Lepidoptera scale, which also furnished when 

 charred the appearance of the " notes " ! ! and of " beads," would, when 

 placed facing each other, furnish an image of beading after the views 

 of Dr. Pigott, when direct sunlight was allowed to traverse them. 

 Hence a large very rude pencil sketch (Fig. 31) was made of 

 Fig. 15 ; over this was laid a clean piece of glass ; the " ribs and cross- 

 bars" were then followed roughly with a composition consisting of 

 mastic dissolved in chloroform and just tinged with aureolin (ground 

 for oil painting), and laid on very thickly in the course of the ribs, 

 lightly over the bars. When dry the plate was reversed, and on 

 this was placed another piece of glass ; the ribbings and cross-bars 

 showing through, were then followed in the same manner with a 

 sable pencil charged with a mixture of mastic, wax, and chloroform, 

 untinged and laid on thickly over the ribs, less so over the trans- 

 verse and oblique bars. When dry these glasses were placed oppo- 

 site each other at apertures cut in a narrow box, all the light being 

 excluded from beyond the outer edges of the figures, and then held 

 up to sunlight, the image being received on glass dulled (by amber 

 varnish used cold and allowed to chill), placed at variable distances. 

 After a little patience and manoeuvring a beautiful dotted or beaded 

 image was shown on the glass, all trace of ribs and cross-bars had 

 disai^iJeared. This was several times shown to others, and finally 

 received on a sensitized collodion plate which furnished the negative 

 from which the photograph (Fig. 27) is printed : the lenses were 

 removed from the camera, so that the effect of diffused light through 

 the transparent spaces has given a rather weak image. 



The camera was shifted, the lenses inserted (|- plate, Voight- 

 lander) and eight negatives were taken of different appearances ; un- 

 fortunately in varnishing them the collodion cracked, and too sadly 

 marred the image to be of any use, but the figures of three are added, 

 as also the coarse pencil sketch of Fig. 15. In Fig. 28 a resem- 

 blance exists to one view oi Degeeria domestica. In Fig. 29 several 

 bright-beaded spots will be noticed on the " ribs " and their generally 

 beaded aspect ; a dark shadow between the " ribs " and their 

 coalescence. 



In Fig. 80, to the left of the figure in the negative are two 

 lines composed of distinct small dark spots (" beads " ?), but so much 

 more delicate than the rest of the image, that they are almost lost 

 by printing the detail of the other parts, which, before injury by the 

 action of the varnish on an old collodion, gave a medium image 



* Vide Watson "On Plumules," 'M. M. Journal,' No. VIII., p. 77, and 

 No. XII. 



