39^ Carbon-dioxide Excretion in Man [April 



This is due, in part at least, to the fact that this subject took his 

 heartiest meal in the morning. The excretion of carbon dioxide 

 for B and C, on the other band, was greatest in the evening, since 

 these subjects took their dinner at i P. M. 



The remarkably high excretion shown for A at the evening ex- 

 periment of December 28 (635 mg., while the average for that 

 hour for this subject is only 443 mg.) is explained as follows: 

 This subject went skating in the afternoon of that day and at about 

 2 130 o'clock had the misfortune to break through the ice, becoming 

 wet to the neck. On being rescued, he walked about two miles in 

 his frozen clothing, exposed meanwhile to a strong wind at a 

 temperature of about — 6° C. On reaching his room he took a 

 thorough rubdown, made a change of clothing, rested for one and 

 one half hours, and appeared at the laboratory at the usual hour for 

 the experiments, with the result stated above. It will be noted that 

 all of this subject's values for the following day, especially that of the 

 evening, were much below the average, indicating a reaction from 

 the exposure and excitement of the preceding day. The high ex- 

 cretion of the morning of January 4 is supposed to be due to lunch 

 eaten late on the preceding evening; that of 12 o'clock, January 26, 

 to an exceptionally heavy morning meal ; and the low result of the 

 evening of January 19 to an especially light midday meal. 



The irregularity of results obtained from B are somewhat diffi- 

 cult to explain. Those of the morning of December 27, 30 and 31, 

 were due to lunch eaten late the preceding evening and in the case 

 of the two latter results, also in part to excessive haste to reach the 

 laboratory in time for the regulär experiment. Other high results, 

 especially those of 5 P. M., December 26, and of 12 M., January 

 2, were undoubtedly due to Indigestion. 



Passing now to a study of the relation of carbon dioxide excre- 

 tion to barometric changes, Plate 5 will be found to embody, in the 

 form of curves, the results already given in Table i, with time as 

 abscissae, and milligrams of carbon dioxide per minute as ordinates; 

 it presents curves for A, B and C, together with that for the 

 barometer in millimeters of mercury and of the outdoor temperature 

 in degrees centigrade. The temperature of the room was practically 

 constant throughout the series of experiments. Three curves are 



