THE RESPIRATORY PROCESS 
I 2 I 
Compare results obtained from as large a number of subjects 
as possible to show different types of respiration. 
C. PNEUMOGRAPH RECORD OF RESPIRATORY MOVE¬ 
MENTS. 
A group of four students may conveniently work together in 
making these records. The subject should be dressed as for (A). 
Adjust the pneumograph to the chest at the level of the lower end 
of the sternum. Attach the tube to the tambour, the writing 
point of which rests very obliquely upon the smoked paper carried 
by a slowly revolving drum. When all is adjusted, one student 
may start the drum to revolve, and, with a stop watch, time the 
duration of the experiment to exactly one minute, at the end of 
which time the drum must be stopped. During this time the 
subject should face away from the apparatus, and should breathe 
normally, which may be best accomplished if he fixes his attention 
upon some subject foreign to the experiment. Separate records 
at different tercels on the drum may be made for each student of the 
group. The paper may then be removed, the record carefully labeled 
and passed through a shellac bath. Dry by laying it, smoked side 
up, upon a sheet of filter paper. The records may then be cut apart, 
mounted in the laboratory book, measured and interpreted as to the 
following particulars: 
1. Rate of respiration per minute. 
2. Comparison of duration of the act of inspiration, expiration, 
and the post-inspiratory and post-expiratory pauses. 
3. Comparison of steadiness oj movement of inspiration and 
expiration. 
D. THE MECHANICS OF RESPIRATION (THE “RESPIRA¬ 
TION SCHEME” OF PORTER). 1 
Not more than two students can work conveniently with this 
apparatus at one time. Make the experiments as directed 
(Porter, pp. 506-507). Record the experiments in the form of 
definite complete statements as to the conditions and results. 
1 This apparatus may be obtained from the Harvard Apparatus Company. See 
Porter’s Introduction to Physiology. 
