1880.] 
25 
The Hon. Henry Cavendish . 
and during by far the greater part of that time either as 
Dire(5tor or Director- General of the Survey. During this 
long period, in addition to his official labours in advancing 
our knowledge of the geology of this country, he has pub- 
lished works on the “ Geology of Arran,” “ The Geology of 
North Wales,” “ The Old Glaciers of North Wales and 
Switzerland,” and “ The Physical Geology and Geography 
of Great Britain,” now in its fifth edition. His papers in 
the “ Quarterly Journal of the Geological Society, and 
elsewhere, are numerous and important, especially those on 
theoretical questions in physical geology, such, for instance, 
as “ The Glacial Origin of Lake Basins,” “The Fresh- 
water Formation of the Older Red Rocks,’ and lhe 
History of the Valley of the Rhine, and other Valleys of 
Erosion.” There are, indeed, among living geologists few 
who can claim to have done more to extend our knowledge 
in the important fields of geology and physical geography. 
The Davy Medal has been awarded to P. E. Lecoq de 
Boisbaudran. The discovery of the metal gallium is 
remarkable for having filled a gap which had been previously 
pointed out in the series of known elements. Mendelejeft 
had already shown that a metal might probably exist, inter- 
mediate in its properties between aluminium and indium, 
before Boisbaudran’s laborious spectroscopic and chemical 
investigation of numerous varieties of blende led him to the 
discovery and isolation of such a metal. 
The separation of the minute traces of gallium com- 
pounds from blende is an operation presenting unusual diffi- 
culty, owing to the circumstance that compounds of gallium 
are carried down by various precipitates . from solutions 
which are incapable by themselves of depositing those com- 
pounds. 
III. THE HON. HENRY CAVENDISH : HIS LIFE 
AND CHARACTER. 
F there is one scriptural admonition which the scientific 
workers of the present day fail to obey more rarely 
than another, it is the one which warns us against the 
foolishness of hiding our light under a bushel, instead of 
setting it on a hill so that it may shine before all men. 
