24 
DR. W. MARCET OR A CHEMICAL IRQUIRY INTO 
2 ^0 4 Hours after Food. 
The three Highest and three Lowest Pressures and corresponding Relations. 
1st group. 
2nd „ 
—Mean highest barometer . 
Mean lowest barometer . 
mm. 
768-8 
741-7 
Relations . 
5> • 
Litres. 
.9-270 
.9-260 
Difference . . . . 
27-1 
Fall for 27'1 mm. = O'OIO 
4 ^0 6 Hours after Food. 
The six Highest and six Lowest Pressures and corresponding Relations. 
mm. 
Litres. 
1st group. 
—Mean highest barometer . 
771-7 
Relations . 
.10-097 
2nd „ 
Mean lowest barometer . 
738-0 
Difference . . . . 
33-7 
Fall for 33-7 mm. = 0'432 
Therefore, from the present enquiry with reference to this person under experiment, 
and a similar remark applies to the other, the relations are invariably found to 
be lowered with falling pressures; or, in other words, with a falling atmospheric 
pressure the volume of air breathed to expire 1 grm. COo is lessened. This is shown 
very clearly by a consideration of the ultimate results obtained from the present 
table, these are as follows :—■ 
From the Collective Readings. 
Fall of barometric 
pressure. 
Fall ill the volume 
of air breathed for 
3 grm. 00 . 1 . 
111 m. 
J.itres. 
0 to 2 hours after food 
11-9 
U-195 
2 to 4 hours after food 
19-3 
0T42 
4 to 6 hours after food 
20-2 
0-154 
Mean. 
17-1 
0-164 
Therefore for a mean fall of 17'1 mm. pressure tliere was a mean reduction of 
OH 6 4 litre in the air breathed to expire 1 grm. COo, amounting to a reduction of 
0'09G0 litre in the volume of air breathed for a fall of pressure of 10 mm. 
The extreme readings for barometer and relations (extreme halves of eacli group) 
gave much greater differences except in one case, to which special reference will be 
made ; they are as follows :—■ 
