﻿ORGANISM 
  AND 
  MECHANISM 
  111 
  

  

  of 
  natural 
  proteins. 
  Even 
  these 
  are 
  being 
  approached, 
  and 
  

   their 
  synthesis 
  will 
  probably 
  be 
  effected 
  too. 
  

  

  Chemically 
  regarded, 
  living 
  involves 
  a 
  complex 
  of 
  re- 
  

   actions 
  in, 
  or 
  associated 
  with 
  the 
  material 
  which 
  we 
  call 
  

   i 
  protoplasm 
  ' 
  and 
  some 
  of 
  these 
  reactions 
  can 
  be 
  re- 
  

   produced 
  apart 
  from 
  the 
  organism 
  altogether. 
  There 
  are 
  

   oxidations 
  and 
  reductions, 
  hydrations 
  and 
  de-hydrations, 
  

   fermentings 
  and 
  so 
  on, 
  which 
  taken 
  separately 
  may 
  be 
  

   mimicked 
  in 
  the 
  laboratory. 
  By 
  freezing 
  tissues, 
  grinding 
  

   them 
  in 
  a 
  mortar, 
  and 
  thawing 
  and 
  filtering 
  the 
  result, 
  a 
  

   non-living 
  material 
  can 
  be 
  obtained 
  in 
  which 
  some 
  chemical 
  

   reactions 
  go 
  on. 
  These 
  can 
  be 
  studied 
  in 
  isolation, 
  and 
  

   this 
  is 
  one 
  of 
  the 
  everyday 
  methods 
  of 
  bio-chemistry. 
  

   Similarly, 
  chemical 
  laws 
  are 
  of 
  indispensable 
  assistance 
  in 
  

   enabling 
  us 
  to 
  understand 
  how 
  the 
  blood 
  carries 
  oxygen 
  and 
  

   carbon 
  dioxide 
  and 
  how 
  digestive 
  juices 
  change 
  the 
  food 
  in 
  

   the 
  stomach. 
  

  

  In 
  the 
  same 
  way 
  it 
  is 
  certain 
  that 
  well-known 
  physical 
  

   processes 
  occur 
  in 
  the 
  living 
  body. 
  Capillarity 
  plays 
  some 
  

   part 
  when 
  sap 
  ascends 
  in 
  a 
  tree, 
  and 
  evaporation 
  plays 
  some 
  

   part 
  when 
  the 
  leaves 
  droop 
  in 
  the 
  summer 
  heat. 
  Surface- 
  

   tension 
  is 
  illustrated 
  when 
  an 
  egg-cell 
  becomes 
  spherical, 
  

   and 
  the 
  elasticity 
  of 
  connective 
  tissue 
  when 
  a 
  hen 
  turns 
  

   suddenly 
  from 
  scanning 
  the 
  sky 
  to 
  inspect 
  a 
  minute 
  seed 
  

   on 
  the 
  ground 
  at 
  her 
  feet. 
  We 
  illustrate 
  the 
  action 
  of 
  levers 
  

   when 
  we 
  walk, 
  and 
  the 
  properties 
  of 
  lenses 
  when 
  an 
  image 
  

   is 
  formed 
  on 
  our 
  retina. 
  All 
  physiologists 
  are 
  agreed 
  that, 
  

   in 
  the 
  description 
  of 
  bodily 
  functions, 
  the 
  formula? 
  of 
  

   chemistry 
  and 
  physics 
  carry 
  us 
  some 
  way. 
  

  

  And 
  just 
  as 
  the 
  fundamental 
  chemical 
  fact, 
  that 
  no 
  in- 
  

   crease 
  or 
  decrease 
  of 
  matter 
  ever 
  occurs 
  in 
  a 
  closed 
  system, 
  

   holds 
  true 
  for 
  the 
  living 
  body 
  and 
  its 
  environment, 
  so 
  it 
  

  

  