ADDRESS. 



27 



all physiological work, while in all this there must be an adaptiveness 

 to purpose as great as any claimed for the most complicated organism. 



From the facts which have been now brought to your notice there is 

 but one legitimate conclusion — that life is a property of protoplasm. In 

 this assertion there is nothing that need startle us. The essential pheno- 

 mena of living beiugs are not so widely separated from the phenomena of 

 lifeless matter as to render it impossible to recognise an analogy between 

 them : for even irritability, the one grand character of all living beings, 

 is not more difficult to be conceived of as a property of matter than the 

 physical phenomena of radial energy. 



It is quite true that between lifeless and living matter there is a vast 

 difference, a difference greater far than any which can be found between 

 the most diverse manifestations of lifeless matter. Though the refined 

 synthesis of modern chemistry may have succeeded in forming a few 

 principles which until lately had been deemed the proper product of 

 vitality, the fact still remains that no one has ever yet built up one par- 

 ticle of living matter out of lifeless elements— that every living creature, 

 from the simplest dweller on the confines of organisation up to the 

 highest and most complex organism, has its origin in pre-existent living 

 matter — that the protoplasm of to-day is but the continuation of the 

 protoplasm of other ages, handed down to us through periods of inde- 

 finable and indeterminable time. 



Yet with all this, vast as the differences may be, there is nothing 

 which precludes a comparison of the properties of living matter with 

 those of lifeless. 



When, however, we say that life is a property of protoplasm, we 

 assert as much as we are justified in doing. Here we stand upon the 

 boundary between life in its proper conception, as a group of phenomena 

 having irritability as their common bond, and that other and higher 

 group of phenomena which we designate as consciousness or thought, 

 and which, however intimately connected with those of life, are yet 

 essentially distinct from them. 



"When the heart of a recently killed frog is separated from its body 

 and touched with the point of a needle, it begins to beat under the exci- 

 tation of the stimulus, and we believe ourselves justified in referring the 

 contraction of the cardiac fibres to the irritability of their protoplasm as 

 its proper cause. We see in it a remarkable phenomenon, but one never- 

 theless in which we can see unmistakable analogies with phenomena 

 purely physical. There is no greater difficulty in conceiving of contrac- 

 tility as a property of protoplasm than there is in conceiving of attraction 

 as a property of the magnet. 



When a thought passes through the mind, it is associated, as we have 

 now abundant reason for believing, with some change in the protoplasm 

 of the cerebral cells. Are we, therefore, justified in regarding thought 

 as a property of the protoplasm of these cells, in the sense in which we 



