EIGHTEENTH ORDINARY MEETING. 221 
lower animals are more or less blind than we. From his experiments 
on ants, Sir John Lubbock concludes that they are nearly or quite 
blind to red and yellow rays, and sensitive to green, blue, violet and 
ultra-violet rays. A photograph taken with silver chloride, which is 
very imperfect to us because the red and yellow rays are not repre- 
sented, and violet and ultra-violet appear very bright, would therefore 
to the critical eye of an ant appear quite correct.” 
Dr. Bryce and Mr. VanderSmissen made remarks on the 
subject, after the reading of the paper. 
NINETEENTH ORDINARY MEETING. 
The Nineteenth Ordinary Meeting of the Session 1883-84 
was held on Saturday, March 22nd, the President in the 
chair. 
The minutes of last meeting were read and confirmed. 
The following list of donations and exchanges was read : 
1. Selected Papers of the Rensselaer Society of Engineers, Vol. 1, No. 1, 
January, 1884. 
. Transactions of the Manchester Geological Society, Vol. 17, Part 13. 
. Weather Review for February, 1884. 
. List of Fellows 1884, Royal Microscopical Society. 
Science, Vol. 3, No. 58, March 14th, 1884. 
. Proceedings of the Royal Geographical Society, Vol. 6, No. 3, March, 1884. 
ao pwn 
Mr. W. J. Loudon, B. A., read a paper on the “ Radiometer,”’ 
illustrated by experiments. 
The following members made observations on the subject: 
Mr. H. S. Howland, jun., Mr. Murray, Mr. Macdougall, Mr. 
McKenzie, Mr. Livingstone and Dr. Bryce. 
TWENTIETH ORDINARY MEETING 
The Twentieth Ordinary Meeting of the Session 1883-84 
was held on Saturday, March 29th, the President in the 
Chair. 
The minutes of last meeting were read and confirmed. 
