g6 Proceedings. 



as the rays appear to be found in some phosphorescent 

 states of natural substances, but not in the solar rays or 

 in the electric arc. A discussion ensued, in which 

 Professor Dixon, Professor Reynolds, and Mr. W. 

 Thomson took part. 



Dr. Schuster also described experiments of his own,, 

 from which he has found that it is impossible to keep 

 an electroscope charged when a beam of the Rontgen 

 rays is passing at a distance of about i inch from the 

 plate. 



Ordinary Meeting, March 31st, 1896. 

 Henry Wilde, F.R.S., President, in the Chair. 



The thanks of the members were voted to the donors 

 of the books upon the table. 



Mr. C. L. Barnes, M.A., showed a method of pro- 

 ducing Lissajous' curves by drawing a sine-curve on a 

 sheet of celluloid, which is then bent into a cylinder of 

 varying diameter. He also exhibited a specimen of 

 writing by the telautograph, an instrument for copying 

 writings and drawings at a distance by electricity. 



Mr. Thorpe showed a diffraction grating on speculum 

 metal by Professor Rowland, of Johns Hopkins University, 

 which divides the helium line in the solar spectrum. 



Mr. W. E. Hoyle, M.A., exhibited some fine butter- 

 flies of the genus Papilio, presented to the Manchester 

 Museum by Lieut. Ellis Leech and other travellers in 

 the West of Africa ; as well as a series of the land shells 

 of the Sandwich Islands, almost the whole of which 

 belong to the family A chatinellidcz. This group is almost 

 peculiar to these islands, where it presents many slightly 

 different varieties, each valley often possessing its own. 

 A discussion on questions of mimicry and other matters 

 suggested by the specimens followed. 



