'2 ENERGY TRANSFORMATIONS 



but little regarding the constitution and structure of living 

 matter. 



Although the intermediate stages in the process cannot be 

 followed by any means at present known to us, we can learn 

 something by watching the ends of the process, by noting the 

 ingesta and egesta of the living matter, and studying qualitatively, 

 and quantitatively, the energy changes- displayed by living matter. 

 As a result of such observations, it is found that the two funda- 

 mental laws of the inorganic world, namely, the conservation of 

 matter and the conservation of energy, are obeyed throughout 

 the whole range of organised nature. Both these laws can be as 

 well demonstrated by using a living animal, and making a debit 

 and credit account for the inatter and energy taken in and given 

 out, as by performing a combustion experiment or causing any 

 other transformation of energy and matter by means of non-vital 

 matter and non- vital energy- transformers. We see that this 

 must be so when we consider that living matter is formed from 

 the same material sources as non-living matter, and, further, 

 that both its building up and its sources of energy for all its 

 changes, when built up, arise from non- vital forms of energy ; 

 thus the same fundamental laws must apply to it as to the in- 

 organic world, for otherwise no balance could exist between the 

 two domains. 



It by no means follows from this, however, that there is no 

 difference except complexity of structure between living and non- 

 living matter, that there is no form of energy peculiar to living 

 matter, and that if we only knew how to apply to living plants 

 and animals the laws pertaining to the forms of energy found in 

 inorganic nature, we should find nothing superadded, nothing to 

 justify such terms as living or vital. The very existence of such 

 words as " living " and " vital " indicate the primary conception 

 of something essentially different in nature, and it ought to be 

 noted that it is the presence of certain peculiar energy phenomena 

 which gives rise to the necessity for introducing such words, and 

 not complexity of structure or development. We call things 

 living because of the energy changes they exhibit, and not because 

 they are complex chemically or physically. Further, when these 

 peculiar energy phenomena are gone, the objects are dead, and 

 even during life they are more typically living the more markedly 

 they chance to show the distinctive energy phenomena of life. 



