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A History of the Fishes of Massachusetts. By David Humphreys 

 Storer, M.D., A.A.S. 4to. — From the Author. 



Maritime Conference, held at Brussels, for devising an uniform System 

 of Meteorological Observations at Sea, August and September 

 1853. 4to. — From the Belgian Academy. 



Monday, 20th March 1854. 



Sir T. M. BRISBANE, Bart., President, in the Chair. 



The following Communications were read : — 



1. On the Total Invisibility of Red to certain Colour- Blind 

 Eyes. By Dr George Wilson. 



After some remarks on the peculiar difficulties which attend in- 

 vestigations into the functions of the eye, the author observed, that 

 by far the most remarkable variety of colour-blindness, in a scientific 

 point of view, is that which shows itself in the identification of red 

 with black. This appeared to have been overlooked by previous 

 observers, or at least only cursorily described. The probable causes 

 of this neglect were noticed ; and the author then proceeded to detail 

 the experience of some twelve parties by whom various objects of a 

 red, crimson, or scarlet colour were mistaken for black, and appeared, 

 from the testimony of those who committed the mistakes in question, 

 to have made neither a colorific nor a luminous impression on the re- 

 tina. It was further shown, that though the fact had not attracted 

 attention, the published cases of colour-blindness supplied examples 

 of the same blindness to red ; and that Dalton, although he had ap- 

 parently ascertained his own freedom from the blindness in question, 

 had incidentally supplied proof that the red alike of the solar spec- 

 trum and of coloured objects frequently appeared to him as dark or 

 nearly black. 



Experiments were also recorded, which had been made by the 

 author, with the assistance of Professor Kelland, on the visibility of 

 prismatic spectra to persons affected by colour-blindness, one of 

 whom was found unable to perceive from ^th to |th of the red end 

 of the solar spectrum, whilst the other could not discern ^d of the 



