190 Annals of the Philosophical Club 



Feb. 29th, 225th meeting. Professor Cornu (see p. 186) 

 (guest) mentioned that he had obtained the reversal of several 

 of the spectral lines of certain metals by placing the metal or 

 its chloride in the path of either the induction spark or the 

 electric arc : namely aluminium, sodium, lead, copper, and 

 thallium, one line ; silver, two lines ; magnesium, zinc, and 

 cadmium, three lines. He had failed to get reversal of any 

 lines in iron, cobalt, bismuth, antimony, or gold. He had 

 come to the conclusion that a very thin layer of vapour (so- 

 thin as to be imperceptible at the distance of the earth from 

 the sun) was sufficient for this reversal. But he thought it 

 needless to assume that a continuous atmosphere, however 

 thin, existed around the sun, the absorption being always 

 local, and taking place spontaneously by the external 

 refrigeration around each incandescent point. 



Mr. J. Evans exhibited some objects of bronze and their 

 moulds, belonging to the later part of that period, from 

 a find at Harty in Sheppey. 



Mr. Sclater stated that the Zoological Gardens had recently 

 received a living specimen of Rhinoceros Sumatrensis. 1 



March 25th, 226th meeting. Mr. Spottiswoode, referring 

 to Professor Cornu's communication to the last meeting, 

 said that on observing with his large automatic spectroscope 

 the spectrum of metallic sodium in a Bunsen burner he 

 had noticed a well-defined absorption line on the centre 

 of each of the bright lines D^ and D 2 , giving them the 

 appearance of being double. The absorption lines therefore 

 were much narrower than the corresponding bright lines. 



April 23rd, 227th meeting (anniversary). Professor 

 Huxley, who had recently returned from Egypt, said he had 

 been very much impressed by the signs of aerial denudation 

 in the valley of the Nile, though the climate apparently 

 was almost rainless. 2 



1 Afterwards it gave birth to a calf. W. T. Blanford, Fauna of British 

 India (Mammalia), page 477. 



1 The word ' aerial ' must refer, I think, to action of streams rather than 

 of winds. In that sense it is very conspicuous above Cairo between the 

 right bank of the Nile and the eastern hills. See A. J. Jukes-Browne, 

 Geol. Mag. 1877, page 477. 



