CONCLUSION. 309 



attend our conception correspond with exciting motions 

 in the object that occasions it, and that these, rather 

 than anything resembling our conception itself, should 

 be regarded as the reality. 



This leads to a third matter, on which I can only 

 touch with extreme brevity. 



Different modes of motion have long been known 

 as the causes of our different colour perceptions, or at 

 any rate as associated therewith, and of late years, 

 more especially since the promulgation of Newlands' * 

 law, it has been perceived that what we call the 

 kinds or properties of matter are not less conditioned 

 by motion than colour is. The substance or essence 

 of unconditioned matter, as apart from the relations 

 between its various states (which we believe to be its 

 various conditions of motion) must remain for ever 

 unknown to us, for it is only the relations between 

 the conditions of the underlying substance that we 

 cognise at all, and where there are no conditions, 

 there is nothing for us to seize, compare, and, hence, 

 cognise ; unconditioned matter must, therefore, be as 

 inconceivable by us as unmattered condition;! but 

 though we can know nothing about matter as apart 

 from its conditions or states, opinion has been for some 

 time tending towards the belief that what we call the 

 different states, or kinds, of matter are only our ways 



* Sometimes called MendelejefE'e (see " Monthly Journal of Science," 

 April 1884). 



t I am aware that attempts have been made to say that we can con- 

 ceive a condition of matter, although there is no matter in connection 

 with it — as, for example, that we can have motion without anything 

 moving (see "Nature," March 5, March 12, and April 9, 1885) — but I 

 think it little likely that this opinion will meet general approbation.. 



