﻿200 
  On 
  the 
  Theory 
  of 
  Ventilation. 
  [Jan. 
  28, 
  

  

  Assuming 
  the 
  average 
  carbonic 
  acid 
  per 
  head 
  to 
  be 
  0*6 
  of 
  a 
  cubic 
  foot, 
  

   these 
  amounts 
  indicate 
  a 
  supply 
  of 
  air 
  as 
  follows 
  : 
  — 
  

  

  Barracks. 
  Hospitals. 
  

  

  Amount 
  of 
  air 
  supplied 
  per 
  head 
  per 
  hour 
  in 
  cubic 
  

  

  feet 
  3062 
  3822 
  

  

  Stated 
  in 
  round 
  numbers, 
  therefore, 
  we 
  may 
  say 
  that 
  while 
  a 
  barrack- 
  

   room 
  may 
  be 
  kept 
  sweet 
  with 
  3000 
  cubic 
  feet, 
  it 
  will 
  take 
  4000 
  to 
  

   keep 
  a 
  hospital 
  ward 
  containing 
  ordinary 
  cases 
  in 
  the 
  same 
  condition. 
  

   Much 
  more 
  would, 
  of 
  course, 
  be 
  required 
  during 
  times 
  of 
  epidemic 
  or 
  

   the 
  like. 
  

  

  There 
  is 
  less 
  regularity 
  in 
  the 
  higher 
  orders 
  ; 
  but 
  if 
  the 
  whole 
  of 
  the 
  

   observations, 
  other 
  than 
  No. 
  1, 
  are 
  taken 
  together, 
  we 
  find 
  a 
  similar 
  

   indication 
  : 
  — 
  

  

  Barracks. 
  Hospitals. 
  

  

  Mean 
  amount 
  of 
  carbonic 
  acid 
  per 
  1000 
  volumes, 
  as 
  

  

  respiratory 
  impurity, 
  in 
  all 
  the 
  observations, 
  when 
  

  

  the 
  organic 
  matter 
  was 
  appreciable 
  by 
  the 
  senses. 
  . 
  0-601 
  0-580 
  

   Number 
  of 
  analyses 
  in 
  each 
  group 
  274 
  86 
  

  

  Calculating 
  the 
  amount 
  of 
  air 
  supplied 
  as 
  above, 
  we 
  have 
  : 
  — 
  

  

  Barracks. 
  Hospitals. 
  

  

  Amount 
  of 
  air 
  supplied 
  per 
  head 
  per 
  hour 
  in 
  cubic 
  

   feet 
  998 
  1034 
  

  

  A 
  comparison 
  may 
  also 
  be 
  made 
  by 
  attaching 
  a 
  numerical 
  value 
  to 
  each 
  

   order, 
  which 
  we 
  may 
  do 
  by 
  making 
  the 
  mean 
  carbonic 
  acid 
  of 
  No. 
  1 
  unity, 
  

   and 
  finding 
  its 
  ratio 
  to 
  the 
  others 
  thus 
  : 
  — 
  

  

  No. 
  of 
  order. 
  

  

  Mean 
  respiratory 
  

   impurity 
  as 
  

  

  co 
  2 
  . 
  

  

  Eatio, 
  No. 
  1 
  

   being 
  unity. 
  

  

  Differences. 
  

  

  1. 
  

  

  0-1830 
  

  

  1-00 
  

  

  

  o. 
  

  

  0-3894 
  

  

  2-13 
  

  

  1-13 
  

  

  3. 
  

  

  0-6322 
  

  

  346 
  

  

  1-33 
  

  

  4&5. 
  

  

  0-8533 
  

  

  4-66 
  

  

  1-20 
  

  

  The 
  progression 
  is 
  pretty 
  regular, 
  and 
  the 
  mean 
  difference 
  is 
  1*22, 
  

   which 
  differs 
  but 
  little 
  from 
  the 
  individual 
  terms. 
  

  

  