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that their use was in keeping the two surfaces of the scale apart, and they 

 were longer or shorter according to whether the surfaces were more or less 

 rounded. He had seen some of the appearances, but only by taking too 

 deep a focus. As for the beading, he had never seen it, and he was strongly 

 inclined to the belief that it arose from Dr. Pigott's methods being in some 

 way at fault. He believed from what he had read that Dr. Pigott worked 

 with a very small aperture, and if anyone wanted to produce false appear- 

 ances they could not go a better way to work ; and by using the lowest 

 aperture of the condenser the same effects could be produced. With regard 

 to the test rings, he knew that appearance perfectly well; but it was again 

 a false effect due to the results of using too small an aperture. 



Prof. B. T. Lowne said he had not given very much attention to this sub- 

 ject, and therefore did not feel competent to enter very fully into it; but 

 his own impression was that the lepidopterous scales consisted of two mem- 

 branes united, or rather kept apart, by vertical rods passing between the 

 two. With regard to their origin, that of course was a different question 

 altogether ; but he was inclined to think that they were mostly regular and 

 had no morphological value whatever. 



The President said that he had no doubt whatever that in the case of 

 some of the scales of lepidoptera there were two surfaces resembling a very 

 much flattened sack, and that these surfaces were joined together by pillars. 

 Of course this fact could not be considered to prove that the surfaces were 

 necessarily flat, neither did he suppose that there were not also small 

 pillars upon the surface ; but that they were attachments inside was a thing 

 he had very little doubt about, although he should say that he had not 

 investigated the minute structure of butterfly scales. 



The thanks of the meeting were voted to Dr. Pigott and Mr. Curties, also 

 to Mr. Niblett for his assistance in exhibiting the specimens. 



Mr. J. T. Niblett, by invitation of the President, exhibited and described 

 the electric lamps which had been used upon this occasion. They were of 

 the ordinary type of incandescent lamps with carbon filaments in vacuo, but 

 the novel and interesting feature about them was due to their being worked 

 by the new Schanschieff primary battery, which not only went into a small 

 compass, but would efficiently afford the necessary current for ten hours with 

 once charging. The remarkable energy of this battery was chiefly due to 

 the exciting fluid (a strong solution of sulphate of mercury), which, being 

 decomposed by the action, ultimately resolved itself into sulphate of zinc and 

 metallic mercury, the latter being a valuable product, and one which, by its 

 reconversion into sulphate, could be used repeatedly, whilst loz. of the 

 solution would furnish an equivalent of two hours' work with an electromo- 

 tive force of 1*39 volts. The microscope lamp exhibited was fixed upon the 

 outside of a small mahogany case, which contained a battery of four cells. 

 When the light was required the battery plates were lowered into the solu- 

 tion, and the carbon filaments at once glowed with full intensity. The 

 chemical action being somewhat powerful, it was necessary to raise the plates 

 from the fluid when the light was no longer required. At the end of ten 

 hours the solution would require renewing, and new zinc plates would be 



