684 
DE. E. smith on the CHEjMICAE 
Bowing of a .odel in the pc— of the Eoyal Society, showing the “^"“Irge^sl 
potash-hoi. There is a series of luXItSes, through which the air is passed 
into the bottom chamber, and through the P ^ Jr. o' fhp exneriment by turning the iimer 
and out of each chamber separately. The opennrgs are closed dnrmg the expenment by 
tube half round its axis. 
of exertion), a double set was used at the same time. By some of 
enabled to make experiments in sleep, as well as m wokefotoess and 
othermodesofexertion, aswellasatrest; alsoforoneorany imi e num n.,,fintev- 
as well as for hours, and ewen for the whole day, continuously, except dunng ^ 
S the fallacy attaching to the different composition 
rdk-ent volumes or cui-reuts of the expired ah' by abstracting the 
L whole; and the duration of each inquiry permitted me 
rt,n influenre of the mind when directed to the respu-atiou, and of inteiimg , 
“u quantities. In addition to this, I have endeavoured to give a more senal and 
extended character to the investigations than any recorded 
n.. — r— , “ “ X:.“i 
r r Zo” X- 
air inspired, and the amount of found that the 
of vapour exhaled was also in a few instances determined, but it was to 
addiln of this subject would render the inquiry too burdensome, and incapable 
repetition with sufficient frequency. 
Tn the following communication I propose to show 
ae qLtity of carbonic acid evolved, and the changes lu f 
wiLut exertion, and with and without food, in the twenty-four hours of the day. 
II. The variations from day to day, and from season to season. 
III. The influence of walking and the treadwheel. 
