1876.] — ^^ [Hartshorne. 



pose as a hypothetical explanation of these results, the throwing of 7'er? light 

 upon the retina hy the liglit of the candle passing through the blood veKxeU 

 of the eyeball; this red light, in the eye most illuminated, killing the red- 

 light vibrations of the retinal elements, so that only green is seen. The 

 pale red of the image seen by the unilluminated eye is, with me, of doubt- 

 ful distinctness. 



If the facts and arguments which I have set forth in this paper impress 

 other minds as they have done my own, especially in vievv of the instan- 

 taneousness o? \wM\j of the phenomena described, and on which I have 

 wislied to lay particular emphasis, it may, at least, be concluded, that the 

 commonly accepted theorj% proposing to account for negative and comple- 

 mentary spectra by partial /a^t^rwe and diminished sensibility in the retina, 

 will not suffice; and ought to be abandoned, as not at all reconcilable with 

 several clearly demonstrable fiicts. Should my above attempted explanation, 

 by interference (or saturation of the retina with certain luminous rays, and 

 neutralisation of a portion of the same by equivalent ra>'s present in re 

 fleeted white light), not prove altogether satisfactory, it may be an inter- 

 esting task, not without importance in physiological science, for some one 

 well -versed in the phj^sics of the subject to give it such farther attention as 

 may solve the problem, in a manner which meets, as has certainly not 

 hitherto been done, all of its conditions. I ask leave to verifj'^ some of my 

 assertions as to the facts referred to in this paper, bj^ repeating here a few 

 of what appear to me the most decisive of the experiments which have 

 been mentioned. 



Stated 3feeti7ig, April 7, 1876. 



Present, 10 members. 



Dr. LeConte, in the Chair. 



Letters of acknowledgment were received from the Ba- 

 tavian Society at Rotterdam (XV ii, 94); the Royal Obser- 

 vatory at Bruxelles (XV ii, 94) ; the Royal Astronomical 

 Society (XIV) ; the Society of Antiquaries (95), and the 

 Victoria Institute in London (95). 



Letters of envoy were received from the Zoologico-Bo- 

 tanical Society at Vienna, March, 1876, and the Meteorologi- 

 cal Office at London, dated March 20, 1876. 



A letter requesting missing N^os. XIV, ii,62, 88 was re- 

 ceived from the R. Astronomical Society, dated February 

 16, 1876. 



