100 ORGANIC FUNCTIONING 



The limits of measurement. Further, physiological measure- 

 ments in the present state of science usually involve the use of 

 the chemical balance, the thermometer, galvanometer, time- 

 recording instruments, etc. So far as these are concerned, the 

 quantities equated usually balance within certain limits of error. 

 But in the physics of radiation much more minute quantities are 

 now significant. Thus infinitesimal and hardly measurable 

 quantities of electric energy impinge on the " grid " of a wireless 

 valve and lead to large effects. Comparable with this are, quite 

 certainly, hosts of life-phenomena — for instance, the occurrences 

 in a nerve-synapse (see Section 41 a). 



So that the law of conservation is true for life -phenomena so 

 far as gross chemico-physical measurements go. 



Finally, the law of conservation is an a priori one : it is some- 

 thing that we postulate. No physical result can invalidate it 

 (either in physics or in physiology). If precise measurements 

 appeared to invalidate it we should merely look for, and find, 

 new forms or phases of energy that would save the " law " (see 

 Section 22h). 



38^. The Law of Dissipation. This holds for the organism 

 with all the strictness that it holds for inanimate systems. In all 

 life-processes some energy is dissipated and entropy increases. The 

 law expresses an inevitable, ultimate tendency and result : 

 entropy always increases in every process which involves the 

 whole universe. Every experimental, or scientifically localized, 

 process does involve the whole universe, since the physicists' 

 isolated physico-chemical system is only a convenient fiction. 

 The experimenter, or the unconsciously acting organism, can 

 cause entropy to decrease locally, but only by causing it to 

 increase somewhere else outside the *' isolated system." 



The organism, and in particular man, can locally and tempor- 

 ally retard entropy-increase by processes of " sorting," control 

 or direction. It is by reason of this sorting, or control, that 

 the organism differs from the inanimate system. 



38^. Modes, Forms and Phases of Energy. Lastly, there 

 are no indications that particular forms, etc., of energy are 

 exclusive to organisms. The visible phenomena of life, so far 

 as these are susceptible of receiving energetic expressions, are 

 expressed in energy ; forms that are the same as those we know 

 in inanimate systems. 



