Annual Report of the Council. 187 



Director of the Observatory at Cambridge from 1861 to his 

 death, and work of the greatest value appears in the Annual 

 Reports. He was never very anxious to publish, and an 

 impression exists that there is much valuable work ready for 

 the printer's hands. Adams was elected an honorary 

 member of this Society on April 20th, 1847. On Airy's 

 retirement, in 1881, the post of Astronomer Royal was 

 offered to him, but declined on the score of age. For a long 

 time he had been in failing health, and unable to do his 

 usual work, and his death, January 21st, 1892, was not 

 unexpected. 



By the death of Hermann Kopp the Society has also 

 lost one of its most illustrious honorary members. Born in 

 1817, he entered upon his scientific studies at Heidelberg 

 in his eighteenth year, devoting himself especially to 

 chemistry and physics. Three years later he passed over 

 to Marburg and took his degree, with a dissertation entitled, 

 " De oxydorum densitatis calculo reperiendae modo." Soon 

 after this we find him engaged at Giessen, under Liebig, 

 carrying out investigations in the borderland of chemistry 

 and physics, whilst interesting himself with kindred prob- 

 lems in meteorology and crystallography. The disserta- 

 tion mentioned above affords, however, an indication of the 

 main direction of his thought, and though occasionally 

 drawn into other channels he pursued with great eager- 

 ness and diligence the study of the relations between 

 the physical and chemical properties of bodies. His 

 observations on the boiling points of liquids, on the 

 expansion of liquids by heat, on the changes of volume 

 during the passage from the solid to the liquid con- 

 dition, on the capacity for heat and the connection which 

 he showed to exist between such properties and the 

 chemical nature of the substance, rank amongst the 

 most important generalisations in the whole region of 



