PHYSIOLOGICAL EFFECTS 151 
trol of the hands, feet, and lips, cold sweat, giddiness, and rapid pulse-rate. 
The symptoms developed very suddenly, as the subject said before the be- 
ginning of the period that he felt perfectly well, this statement being corrob- 
orated by the fact that the pulse- and respiration-rates had both fallen in the 
intermission between the two working periods. He was immediately trans- 
ferred to the couch and after 14 minutes was found to be in extremely good 
condition, the pulse-rate having fallen to 72 and the respiration-rate to 11 per 
minute. As it was thought that the subject might have a weak heart, an 
examination was made by E. P. C, who found no evidence of this. A con- 
firmatory examination was made by Prof. D. L. Edsall who was at that time 
working in the Nutrition Laboratory, and his findings were also negative. 
The experiment on December 13, 1911, with the professional subject 
M. A. M., likewise has an interest in this connection. The three resting- 
periods were without incident, as were also the three periods in which the sub- 
ject rode without load. At ll h 05 m a.m., the current was passed through the 
magnet and the work period began at ll h 21 m a.m. The subject reported 
that he found moving the wheel with resistance very hard work, the effort 
required being more like that necessary for hill-climbing than for track-rac- 
ing. One record of the pulse-rate made during the work showed 116 beats 
per minute. Soon after the period began, the subject looked flushed; a few 
minutes afterwards he perspired freely, and at ll h 25 m a.m. he was obliged 
to discontinue his efforts as he was on the point of collapse. In appearance 
he was wild and scared, his face was pallid, his mouth twitching, and he had 
lost the control of his muscles, being unable to grasp the handle bars or to 
speak when he stopped. 
The subject said that although he had collapsed in races, yet he had 
never felt so ill as he did at this time. He was much chagrined at his failure 
to continue and in order to convince the observers that the apparatus and not 
he was at fault, he again commenced riding, assuming what he called his 
"racing position," in which he lay over the handle-bars with his arms well 
back. With apparent ease and certainly without signs of collapse, he made 
138 to 140 revolutions of the wheel per minute. In this test he did not breathe 
through the mouthpiece. 
On the next day (December 14), the amount of work performed in the 
experiment was controlled by using a metronome, so as to restrict the subject 
to but 60 revolutions per minute. Before the experimental period began, 
the subject rode for a preliminary period of 22 minutes. Throughout the 
working period, while breathing through the apparatus, he was bathed in 
perspiration and at the end of 10 minutes signalled that he could not continue; 
he began to sway in his seat, and the experiment was immediately stopped. 
The records of the pulse-rate for the working period are extremely interesting. 
The experimental period began at 10 h 29 m a.m.; at 10 h 31 m a.m., the pulse- 
rate was 124 per minute; at 10 h 33 m a.m., it was the same; at 10 h 35 m a.m., 
it had risen to 128; at 10 h 37 m a.m., to 134; at 10 h 39 m a.m., to 142; and at 
10 h 39 m 30 s a.m. to 152 per minute, at which time he signalled for the ex- 
periment to be discontinued. The rapid rise in the pulse-rate is character- 
istic of impending collapse which was here present. 
In a third experiment on December 15, the subject also showed signs of 
collapse in the third working-period, although the two preceding periods were 
