8o BIOLOGICAL LECTURES. 



all mechanical movements of it are soon brought to rest. The 

 ether is frictionless. Matter has gravity ; the ether is without 

 it. Hence it is plain that one must not include ether when he 

 is talking about matter, for it is altogether a different some- 

 thing with different and unknown and undiscovered qualities, 

 and no one has been able to deduce the properties of matter, 

 as we know it, from the properties of ether. It is plainly the 

 agency by which light and heat get to us from the sun and stars, 

 by which electric and magnetic phenomena become apparent. 

 Gravity is chargeable to its pressure instead of to the attraction 

 of matter. It transmits wave motions at the rate of 186,000 

 miles a second, but it transmits gravity more than 200,000 million 

 miles a second. Some of the phenomena it exhibits seem to 

 show it to be an enormous storehouse of energy, one million 

 horse power per cubic foot is a low estimate for it. Like astro- 

 nomical distances and magnitudes it may be computed but not 

 conceived. With all this it is entirely incapable of affecting 

 any of our senses. We are without any nerves capable of per- 

 ceiving it, and belief in the existence of such a medium has 

 been forced upon men of science because, first, every former 

 supposition has experimentally broken down ; second, because, 

 as Sir Isaac Newton said, it is impossible to think that one 

 body can act upon another not in contact with it without some 

 kind of a medium between them ; and lastly, because energy does 

 get from one body to another in the absence of ordinary matter, 

 as is exhibited by the heat and light of the sun, and the rate of 

 transference can be measured in several ways. The interpre- 

 tation of the physical facts observed has necessitated it, and by 

 its means otherwise inexplicable difficulties are overcome. I 

 think there is not a physicist of any nation or rank who has 

 attended to the facts, who is not satisfied of the existence of 

 what we call ether, but no one can describe it or tell how it can 

 and how it does act upon matter. We are in almost total igno- 

 rance about it. If it is hazardous to set limits to the possibilities 

 of matter with the advantage of what knowledge we have of it, 

 what shall be said of the attempt to limit the qualities and 

 possibilities of what we know nothing about, ether! The 

 mystery of matter is great, but is nothing to the apparent mys- 



