Dr. Goring on Achromatic Microscopes, 



423 



of the shoptician will in vain attempt to palm worthlesa trash 

 on the ignorance of the public. I here, therefore, enter into 

 the description of the figures in the plate : — i., ii., iii., and 

 iv., have been already sufficiently described* ; I shall therefore 

 merely remark that fig, 1 is a true drawing of the object it 

 is meant to represent, having been originally executed by 

 Mr. Lister with a camera lucida eye-piece ; therefore, my 

 readers will conclude that if they do not find the feather of a 

 supposed Menelaus' butterfly, procured near the origin of 

 the wing, to resemble it pretty closely, they have not ob- 

 tained the same object, more especially if the apertures 

 required to develop its peculiar structure do not correspond 

 with my statement, for this will be the best security for its 

 identity. 



I am indebted to Mr. Carpenter's pro- pig^ 5. 



found erudition in that branch of natural his- 

 story which belongs to the microscope, for 

 the ascertainment of the veritable butterfly 

 to which this feather belongs : my readers 

 may rest assured that it is the Menelaus. 

 Mr. C. has a very fine one in his valuable 

 cabinet. 



Fig. 5, is a drawing of another feather ; 

 it was taken by Mr. Tulley from some frag- 

 ments of wings of foreign insects. Mr. Car- 

 penter has discovered a specimen very simi- 

 lar to it, found on the upper surface of the 

 under wing of the male papilio brassicae, 

 It does not show the curved lines at the 

 double head, and is rather a more difficult 

 object than the sample drawn. It is about 

 T^SiT of an inch long by ■j^%y or -^j,\g broad, 

 of a light brownish, yellow tint, and extreme- 

 ly transparent. In the plate the lines have 

 too much strength and continuity, and are 

 not sufficiently close ; their traces are faint, 

 uneven, dotted, and interrupted here and 

 there. They are not resolvable without 



* Vide the paper and copperplate in the last number of the same old 

 series. 



