SUMMARY. 20 



direct outcome of the condition it indicates, as 

 speech is the direct outcome of respiration and 

 brain action; or the expression and the inherent 

 condition may be found by empirical experience 

 to be uniformly coincident. The expression, or 

 outcome from the subject observed, may be the 

 result of some force afferent to the subject, as the 

 movement of a sensitive flame, which is caused by 

 vibrations of the air, there the physical sign ob- 

 served, the movement of the flame, is an expression 

 of the vibrations of the air. The physical signs 

 observed may express impressionability, temporary 

 or permanent ; in the telephone the receiving plate is 

 very impressionable, but the effect of the vibrations 

 it receives is temporary ; in the phonograph the 

 vibrations received are impressed upon tinfoil, and 

 more or less permanently retained. Impression- 

 ability, temporary or permanent, is frequently 

 expressed in plants, animals, and in man. 



Those cases may be termed " direct expression " 

 where the physical signs observed are the direct 

 outcome of the property expressed ; an " empirical 

 expression " signifies that the physical sign observed 

 is uniformly found by experience to be associated 

 with a certain property, though the line of causation 

 may not be understood. Nutrition is a property 

 belonging only to living beings ; the term denotes 

 an active vital process converting pabulum into 

 tissue, or evolving force which may be observed 

 in action. The results of nutrition may be in part 

 due to external forces afferent to the subject, and 

 so may in part express them. 



