MAGNIFYING POWER OF SHORT SPACES. 11 



circles. When the images which are most distinct, for those 

 near the margin look fainter, assume in the ag-gregate the form 

 of the hexagonal star, which they not unfrequently do, the 

 appearance is striking and uncommon, see fig. 11, Plate I. 



The simplicity of the process by which such a spectacle is 

 produced, together with the novelty of the sight itself, did 

 not tend, of course, to diminish the sense of its gorgeousness ; 

 and I was delighted to find a natural multiplying glass in 

 a tissue, which had already contributed so much to my ad- 

 miration and wonder when examined under a compound 

 microscope. 



On viewing the sun in the same way, each small and per- 

 fectly circular image presented the rainbow tints in the same 

 order, as in fig. 12, Plate I., and the multiplied images of the 

 pale moon were scarcely less beautiful. 



I may remark, in passing, that the taper flame and the 

 image of the moon were seen through a specimen mounted in 

 Canada balsam ; but the rays of the sun were less distressing 

 to the eye when examined through a specimen mounted in 

 the dry way. 



Thus, although I had not, in this experiment at least, suc- 

 ceeded in rendering visible a magnified image of each hexagon 

 in outline, which indeed was the object of my research, I had, 

 in effect, resolved the reticulated structure of the membrane ; 

 for in this way only could the peculiarities of a multiplying 

 medium have presented themselves. The interval between 

 each image served, moreover, to indicate the apparent enlarge- 

 ment of each facet, and thus to give a notion of the magnify- 

 ing power of short spaces. 



Still bearing in mind the comparatively enormous magni- 

 tude imparted to images on bringing the objects which pro- 

 duce them very near to the eye, and recollecting that the image 

 of a mere needle-puncture seen at half an inch is magnified 

 no less than a million times, it was difficult to renounce the 

 idea of the practicability of defining the hexagonal lattice- 

 work of an insect's eye with the naked eye, and without the 

 assistance of a material lens. 



In the former attempt the membrane seemed too opaque to 

 disclose its minute internal configuration, a specimen was 

 therefore now mounted in balsam to increase its transparency. 

 This, however, did not succeed ; on the contrary, it had 

 become so indistinct that its structure could now be scarcelv 

 made out even with a microscope. In order to define the 

 hexagons it was evidently necessary to colour the membrane. 

 A few specimens wei'e macerated, therefore, for four days in a 

 decoction of logwood, and then carefully dried and mounted 



