428 



SCIENTIFIC THOUGHT. 



36. 

 The 



" physical ' 

 method. 



There is, however, a second way open to the student 

 of the phenomena of hfe, and this may be termed 

 the " physical method," as opposed to the " structural." 

 Thus chemists and physicists first establish the general 

 laws of motion and change in dynamics and energetics, 

 and subsequently apply them to special problems, such 

 as those of physical astronomy or the chemistry of 

 electrolysis and solution. Similarly the physiologist 

 may study the processes common to all living matter, 

 and look upon the action of a definite cell, tissue, or 

 organ merely as an application of these general processes. 

 From this point of view structural biology, like struc- 

 tural chemistry, only furnishes illustrations, not an ex- 

 planation, of the vital processes : the special structure 

 or organ is a result of the process or function — 

 not its cause. As Prof. Michael Foster says, " We may 

 throw overboard altogether all conceptions of life as 

 the outcome of organisation, as the mechanical result 

 of structural conditions, and attempt to put physi- 

 ology on the same footing as physics and chemistry, 

 and regard all vital phenomena as the complex pro- 

 ducts of certain fundamental properties exliibited by 

 matter, which, either from its intrinsic nature or from 



plasm. Protoplasm consists of a 

 ground mass in many cases com- 

 pletely homogeneous, in most cases 

 very finely foam-like or honej'comb- 

 like, in which lies embedded a 

 greater or less quantity of very 

 various solid elements or granules. 

 In the foam -like protoplasm the 

 granules always lie at the corners 

 and angles where the foam-vacuoles 

 come together, never in the liquid 

 of the bubbles themselves." Some 

 physiologists think that none of 



the descriptions of protoplasmic 

 architecture help us much, and 

 " hold to the fundamental principle 

 that living matter acts by virtue of 

 its structure, provided the term 

 structure be used in a sense which 

 carries it beyond the limits of ana- 

 tomical investigation — i.e., beyond 

 the knowledge which can be at- 

 tained either by the scalpel or the 

 microscope " (Burdon Sanderson, 

 'Address,' Brit. Assoc, 1889, p. 

 607). 



