﻿246 
  Dr. 
  A. 
  D. 
  Waller. 
  The 
  Physiological 
  Cost 
  of 
  Muscular 
  

  

  and 
  after 
  a 
  brief 
  spell 
  of 
  muscular 
  effort, 
  there 
  is 
  no 
  doubt 
  increased 
  pumping, 
  

   but 
  there 
  is 
  also 
  increased 
  CO2 
  production 
  in 
  the 
  background 
  ; 
  both 
  effects 
  

   are 
  the 
  physiological 
  sequelae 
  of 
  the 
  muscular 
  effort, 
  and 
  the 
  total 
  resultant 
  

   CO2 
  expired 
  is 
  to 
  be 
  regarded 
  as 
  being 
  in 
  measure 
  with 
  the 
  effort 
  that 
  has 
  

   produced 
  increased 
  breathing. 
  I 
  possess 
  a 
  large 
  number 
  of 
  data, 
  extending 
  

   back 
  over 
  many 
  years, 
  by 
  which 
  I 
  have 
  sought 
  to 
  ascertain 
  the 
  quantitative 
  

   relations 
  between 
  work 
  and 
  cost 
  of 
  work 
  — 
  work 
  measured 
  in 
  kgrm.-metres 
  

   per 
  second, 
  cost 
  of 
  work 
  measured 
  in 
  cubic 
  centimetres 
  per 
  second 
  and 
  

   translated 
  into 
  the 
  mechanically 
  equivalent 
  kgrm.-metres 
  — 
  from 
  which 
  I 
  

   may 
  quote 
  an 
  observation 
  and 
  graph 
  on 
  myself, 
  which 
  is 
  given 
  to 
  serve 
  as 
  a 
  

   picture 
  showing 
  the 
  kind 
  of 
  time-relations 
  of 
  a 
  single 
  wave 
  of 
  CO2 
  exhaled 
  

   by 
  the 
  lungs 
  in 
  consequence 
  of 
  a 
  short, 
  sharp 
  muscular 
  effort, 
  i.e., 
  the 
  ascent 
  

   of 
  a 
  20-metre 
  staircase 
  in 
  one 
  minute, 
  i.e., 
  approximately 
  80 
  x 
  20 
  kgrm.-metres 
  

   per 
  minute, 
  or 
  26 
  - 
  7 
  kgrm.-metres 
  per 
  second, 
  or 
  - 
  33 
  horse-power. 
  These 
  are 
  

   rounded 
  figures 
  ; 
  actual 
  figures 
  observed 
  are 
  given 
  in 
  the 
  protocol. 
  

  

  The 
  factor 
  x 
  20 
  for 
  the 
  conversion 
  of 
  cubic 
  centimetres 
  C0 
  2 
  per 
  second 
  to 
  

   Kals 
  per 
  hour 
  is 
  taken 
  as 
  inclusive 
  of 
  an 
  average 
  temperature 
  correction 
  (15°) 
  

   for 
  expired 
  air 
  at 
  an 
  average 
  respiratory 
  quotient 
  (0 
  - 
  85). 
  At 
  0*85 
  respiratory 
  

   quotient 
  the 
  factor 
  is 
  21 
  - 
  081, 
  i.e., 
  5:4 
  per 
  cent, 
  above 
  20. 
  At 
  15° 
  the 
  volume 
  

   of 
  C0 
  2 
  is 
  5*5 
  per 
  cent, 
  above 
  that 
  at 
  0°. 
  So 
  that 
  the 
  factor 
  20 
  practically 
  

   eliminates 
  the 
  two 
  differences, 
  and 
  the 
  result 
  in 
  Kals 
  per 
  hour 
  is 
  substantially 
  

   correct. 
  

  

  The 
  value 
  of 
  resting 
  C0 
  2 
  is, 
  whenever 
  possible, 
  to 
  be 
  actually 
  measured 
  

   and 
  used 
  as 
  a 
  base-line 
  from 
  which 
  to 
  measure 
  net 
  C0 
  2 
  . 
  Practically 
  I 
  take 
  

   as 
  base-line 
  the 
  C0 
  2 
  reading 
  of 
  the 
  subject 
  after 
  sitting 
  at 
  rest 
  for 
  5, 
  or 
  

   preferably, 
  10 
  minutes. 
  When 
  this 
  is 
  not 
  possible, 
  I 
  assume 
  as 
  base 
  line 
  the 
  

   value 
  2 
  c.c. 
  C0 
  2 
  per 
  second 
  per 
  square 
  metre, 
  i.e., 
  40 
  Kals 
  per 
  hour 
  per 
  square 
  

   metre. 
  This 
  value, 
  although 
  perhaps 
  a 
  trifle 
  high, 
  does 
  not 
  sensibly 
  impair 
  

   the 
  correctness 
  of 
  heavy 
  work 
  values 
  = 
  20 
  or 
  30 
  c.c. 
  per 
  second, 
  but 
  it 
  is 
  

   obviously 
  inadmissible 
  for 
  use 
  when 
  the 
  net 
  cost 
  of 
  light 
  work 
  = 
  5 
  to 
  10 
  c.c. 
  

   per 
  second 
  is 
  under 
  examination. 
  In 
  the 
  latter 
  case, 
  at 
  least 
  two 
  direct 
  

   measurements 
  of 
  resting 
  C0 
  2 
  at 
  5 
  minutes' 
  intervals 
  must 
  be 
  taken 
  before 
  

   work 
  is 
  begun 
  and 
  after 
  work 
  has 
  ended. 
  

  

  