1888.] on Antagonism. 287 



bably emanated from two different sources. It was probably of a very 

 high temperature. If this theory of temporary stars be admitted, we 

 get a nebula of vapour or star dust again, and so may get fresh instances 

 of the nebular hypothesis. 



Let us now take the earth itself. It varies in temperature, and 

 consequently the particles at or near its surface are in continuous 

 movement, rubbing against each other, being oxidized or deoxidized, 

 either immediately or through the medium of vegetation. This also 

 is continuously tearing up its surface and changing its character. 

 Evaporation and condensation, producing rain, hail, and storms, 

 notably change it. Force and resistance are constantly at i^lay. The 

 sea erodes rocks and rubs them into sand. The sea quits them, and 

 leaves traces of its former presence by the fossil marine shells found 

 now at high altitudes. Eocks crumble down and break other rocks or 

 are broken by them ; avalanches are not uncommon. The interior of 

 the earth seems to be in a perpetual state of commotion, though only 

 recurrent to our observation. Earthquakes in various places from 

 time to time, and doubtless many beneath the sea of which we are not 

 cognizant, nor of other gradual upheavals and depressions. Through- 

 out it nothing that we know of is at rest, and nothing can move 

 without changing the position of something else, and this is antagonism. 

 Metals rust at its surface, and probably they or their oxides, chlorides, 

 &c., are in a continuous state of change in the interior. Nothing that 

 we know of is stationary. The earth as a whole seems so at first 

 sight, but its surface is moving at the rate of some seventeen miles a 

 minute at the equator ; and standing at either of the poles — an experi- 

 ment which no one has yet had an opportunity of trying — a man would 

 be turned round his own axis once in every twenty-four hours, while 

 the earth's motion round the sun carries us through sj)ace more than 

 a million and a half of miles a day. 



The above changes produce motion in other things. The earth 

 pulls the sun and planets, and in different degrees at different portions 

 of its orbit. 



Before I pass from inorganic to organized matter I had better 

 deal with what may perhaps strike you as the most difficult jjart of 

 my subject, viz. light. Where, you may say, is there antagonism 

 in the case of light ? Light exercises its force upon such minute 

 portions of matter that until the period of the discovery of photo- 

 graphy its physical and chemical effects were almost unknown. Such 

 effects as bleaching, uniting some gases, and affecting the colouring 

 matter of vegetables, were partially known but little attended to ; 

 but photography created a new era : I shall advert to this presently. 

 The theories of light, however, involved matter and motion. The 

 corpuscular theory, as you well know, supposed that excessively small 

 particles were emitted from luminous bodies, and travelled vdih 

 enormous velocity. The undulatory theory, which supplanted it, 

 supposed that luminous bodies caused undulations or vibrations in a 

 highly tenuous matter called ether, which is supposed to exist 



