BIOPHYSICS 



TAirr I. SYSTEMATK^ 

 SECTION I.: ENERGETICS 



CHAPTER I 

 LAWS OF ENERGY 



" There is in reality only one general physics, only one chemistry, anci only one 

 mechanics, in which all the phenomenal manifestations of nature are included, both 

 those of living bodies and those of inanimate ones." Claude Bernard. 



" The history of man is dominated by, and reflects the amount of available energy." 



SODDY. 



Biophysics deals with the appHcation of physical and physico- 

 chemical laws to the actions of living things. It is necessary 

 at the outset to have a clear understanding of what is meant by a 

 natural law, or principle of nature, A law in science is a different 

 concept from a law in philology or in jurisprudence. Repeated 

 observation of a recurring phenomenon leads to the conclusion 

 that there is a natural and unalterable sequence of events. This is 

 summarised in a law. Newton's Law, for instance, epitomises the 

 conclusions of a large series of observations, viz. that objects free 

 to do so always fall towards the earth. A natural law, then, is 

 not a principle governing the action of nature, but a generalisation 

 drawn from observation of the phenomena, stating, in short, how 

 these phenomena have always been known to act in the circum- 

 stances. If the observations are correct, the law is true and, in 

 like circumstances, will always hold. If at any time a reliable 

 observation were made that seemingly went against the law, 

 scientists would not doubt the validity of the law, but would 

 carefully examine the concomitant circumstances to see in what 

 point they differed from those defined in the law. The problem 

 before us is to determine whether laws deduced from the study of 

 non-living matter may be applied to the elucidation of biological 

 phenomena. Physical science is the most finidamental of the 

 experimental sciences and, so far as is known, its laws are applicable 

 to all non-living matter. Biochemists have attempted to break 



