1901-2.] Mr J. Fraser on Constitution of Matter and Ether. 31 
As the opinion of a physicist and mathematician like Sir J. 
Herschel is of far greater weight than that of an obscure 
individual like myself, I make no apology for quoting at some 
length his conclusions on this subject, from his lectures on Light, 
1873 : — 
“ As we have attempted to form an estimate of the forces 
required to account for observed facts on the corpuscular 
hypothesis, let us now attempt a parallel estimate on the 
undulatory. And here the way is equally open and obvious. 
Starting with the observed facts that sound travels in the air at 
the rate of 1090 feet per second, while light is propagated 
through the ether 186,000 miles in the same time (that is to say, 
901,000 times as fast), we are enabled to say how many fold the 
elastic force of air, or its resistance to compression, would require 
to be increased in proportion to the inertia of its molecules , to give 
rise to an equally rapid transmission of a wave through it. For it 
results from the theory of sound that in media of different 
elasticities (so understood), but similarly constituted in other 
respects, these forces are to each other as the squares of the 
velocities with which the waves travel. So that the elastic force 
of the air would require to be increased in the proportion of the 
square of 901,000 ( i.e ., 811,801 millions) to one to produce an 
equal velocity. Even this enormous number must be still further 
increased, since the velocity of sound is augmented by a 
peculiarity in the constitution of the air which we would hardly 
be justified in attributing to the luminiferous ether, in virtue of 
which its elasticity is increased by heat given out in the act of 
compression, and without which the velocity of sound would be 
only 916 feet per second, instead of 1090. Thus the number above 
arrived at has to be further increased in the proportion of the square 
of 1090 to that of 916, which brings it to 1,148,000,000,000. 
Let us suppose, now, that an amount of our ethereal medium 
equal in quantity of matter to that which is contained in a 
cubic inch of air (which weighs about one-third of a grain) were 
inclosed in a cube of an inch in the side. The bursting power of 
air so inclosed we know to be 15 lbs. on each side of the cube. 
That of the imprisoned ether would be 15 times the above 
immense number (or upwards of 17 billions) of pounds. Do 
