438 



SCIENTIFIC THOUGHT. 



41. 



Mobility of 



living 



matter. 



Another property of all living matter which has been 

 seized upon to furnish a definition of life is its extreme 

 mobility. It has been stated that the great difference 

 between living and non-living matter is this that the 

 former is in a state of movable or dynamical equilib- 

 rium, whereas the latter tends always to a condition 

 of rest or of statical equilibrium. This was especially 

 urged by the late celebrated Du Bois-Reymond of 

 Berlin, to whom we owe the greater part of our know- 

 ledge of the physical and chemical changes exhibited 

 in the active nervous system. In comparison with 

 this property of a dynamical equilibrium, explained by 

 the analogy of a fountain of water or a vortex which 

 change their substance whilst maintaining their form, 

 other older distinctions which had been drawn between 

 organised and unorganised bodies sank into insignificance. 1 



or indirectly." (p. 824). Prof. 

 Japp and Prof. Crum Brown of 

 Edinburgh are of the opposite 

 opinion, inasmuch as in the view 

 of the former " the action of life, 

 which has been excluded during 

 the previous stages of the pro- 

 cess, is introduced the moment 

 the operator begins to pick out 

 the two euantiomorphs," as was 

 done by Jungfleisch. 



1 Among the older discussions 

 of the best way of defining life 

 which belong to the second 

 third of the century, we have 

 in Germany the various writings 

 of Du Bois - Reymond ('Reden,' 

 notably vol. ii. p. 25) ; in France 

 those of Claude Bernard ('Pheno- 

 nienes de la vie,' notably vol. i. p. 

 21, &c.) ; in England the ' Biology ' 

 of Mr Herbert Spencer. The two 

 last-named authors examine with 

 some care the definitions of earlier 

 writers. All three should be read 



and re-read by any one who desires 

 to arrive at a clear understanding of 

 the subject. Du Bois-Reymond's 

 definition shows the preponderat- 

 ing influence of the ideas whicli 

 governed the Berlin school of 

 physiology, and which centred in 

 Helmholtz's tract on the Conserva- 

 tion of Energy. Claude Bernard 

 defines life by the words " La vie, 

 c'est la creation." Organisation 

 and disorganisation are the two 

 sides of this process, organisation 

 and environment the two factors. 

 The doctrine of evolution goes a 

 step farther back, and attempts to 

 analyse "organisation." The pro- 

 cess of creation is to Mr Herbert 

 Spencer a process of development. 

 The word creation in the older sense 

 ceases to have a meaning. Of more 

 recent date are the discussions of 

 the subject in the very interesting 

 work of Carl Hauptmann, ' Die 

 Metaphysik in der modern en Physio- 



