THE PHENOMENA OF HUMAN RESPIRATION. 
29 
4 ^0 6 Hours after Food. 
The Three Highest and Three Lowest Barometer Readings and Corresponding Relations. 
Mean highest barometer. 763'4 
Mean lowest barometer. 747’6 
Difference.I5'8 
Litres. 
Relations.II'544 
„ .10-957 
Fall for 15’8 mm. = 0-587 
This Table shows a result corresponding with that obtained from similar experiments 
on William Alderwood. The fall of Barometric readings and corresponding relations 
taken collectively give the following figures ;— 
Taken Collectively. 
Differences of 
Kail ill the volumes 
barometric ijressure. 
of air expired for 
1 grm. COj. 
inm. 
Litres. 
Fall of from 0 to 2 hours after food 
14-1 
0-134 
,, from 2 to 4 hours after food 
12-8 
0-121 
,, from 4 to 6 hours after food 
9-2 
0-390 
Mean. 
12-0 
0-215 
Therefore, for a mean fall of 12 mm. pressure, there was a mean reduction of 
0'215 litre of air breathed for 1 grm. CO^ expired, amounting to a reduction of 
0'179 for 10 mm. 
The Table for extreme readings gives :— 
Differences of 
barometric pressure. 
Fall in the volumes 
of air expired for 
1 grni. CO_. 
mm. 
litres. 
Fall of from 0 to 2 hours after food . 
20-7 
O-306 
,, from 2 to 4 hours after food . 
20-1 
0-202 
,, from 4 to 6 hours after food . 
15-8 
0-587 
Meau. 
18-9 
0-365 
Therefore, with the extreme readings, for a mean fall of 18’9 mm. of the barometer, 
there was a mean fall of 0‘365 litre in the air breathed to expire 1 grm. carbonic 
acid, amounting to a reduction of 0T94 for 10 mm. This is very near to OH79, 
the corresponding figure obtained for the barometer readings and relations taken 
collectively. Consequently, with one person under experiment, the mean reduction 
