208 TRANSACTIONS OF THK 



2nd Maech, 1877. 

 Mr. J. Harvie, Vice-President, in tlie chair, 



SPECIMENS EXHIBITED. 



By Mr. K. H. Paterson. — The jaw of a shark from the South Seas. 



PAPER READ. 



Mr. W. C. Crawford read the first of two papers on the " Spectro- 

 scope in Biology." The author gave an account of the general 

 principles of spectroscopy as applied to the examination of absorption 

 bands produced by coloured liquids. He mentioned the instruments 

 generally employed for obtaining both prismatic and diffraction 

 spectra. The changes on the appearance of radiation spectra from 

 variations in pressure and density were then noticed, aud similarly 

 the effect of the thickness of a coloured solution in modifying the 

 amount of absorption, as well as alterations that arise from 

 temperature, was shown by means of graphic curves. Investigations 

 of this kind seem surrounded by peculiar difficulties, and the results 

 obtained from them are at present rather unsatisfactory. 



After the paper was read a number of characteristic spectra were 

 shown under the micro-spectroscope. 



16th March, 1877. 



Mr. W. J. Milligan, Vice-President, in the chair. 

 It was agreed that the Society should give a contribution to the 

 Hennedy Memorial. 



SPECIMENS EXHIBITED. 



By Mr. R. H. Paterson. — A number of rare mosses collected by 

 himself, among which there were two new to science, which had been 

 called by the Rev. John Fergusson of Brechin, Coscinodon Patersoni 

 and Hyjmtim Scoticum. Both of these were gathered in the summer 

 of 1875. There were also specimens of the following mosses from 

 Kilfinan, Argyleshire : Nechem pennata, H]jpnum pulchellum, H. 

 trifarmn and H. Halhrl See "Scottish Naturalist," April, 1877. 



