Award of the Boyle Medal and Rep. of Sci. Com. R.D.S. 101 
greatest living thinkers have already contributed. If the Royal 
Society has omitted to commemorate him with a medal, it is 
fitting that we should make good the omission and claim what is 
our own. 
Dr. Joly then read the following Report of the Science 
Committee :— 
The name of Dr. G. Johnstone Stoney is recommended 
by the Science Committee as that of a worthy and fit recipient 
of the first Boyle Medal awarded for research in Pure Science. 
In consideration of the many years during which Dr. Stoney’s 
scientific work has been before the world, and the manner in 
which it has stood the test of time, and served as the basis of 
fresh advance—ever the test of true scientific work—your Com- 
mittee feel that this award is but a tardy recognition of his 
labours, and rejoice that it is at length in the power of the Society 
to express its appreciation of such work. 
Dr. Stoney’s work extends into many branches of Science. 
In 1858 he was associated with the late Provost Lloyd in 
making a magnetic survey of the southern half of Ireland. In 
1860 two of his earliest papers appeared in the Transactions of the 
Royal Irish Academy, one explaining the phenomena of rings 
seen in fibrous specimens of cale spar, the other reconciling the 
forward propagation of waves in a uniform medium with the fact 
that from each point of the medium the disturbance is propagated 
equally forwards and backwards. 
His contributions to the Kinetic Theory of Gases are many 
and valuable. The brilliant achievement of first finding a 
numerical estimate of the number of molecules in a unit volume 
of a gas at atmospheric temperatures and pressures is_ his. 
Maxwell had found the mean free path, Clausius and Joule had 
estimated the velocity of mean square, Loschmidt of Vienna had 
first estimated the diameter, but it remained for Dr. Stoney, in a 
paper “On the Internal Motions of Gases compared with the 
Motions of Waves of Light,” which appeared in the Philosophical 
Magazine of August, 1868, to deduce from the work of Clausius 
and Maxwell the number of molecules in a cubic millimetre of a 
gas. 
