PREVIOUS INVESTIGATIONS. 21 



taken. In a typical experiment he finds the oxygen consumption can 

 increase from 4.5 liters in 15 minutes (fasting) to a maximum of 6.12 

 liters after a meal. He lays special emphasis upon glandular activity 

 in the work of digestion, which he thinks accounts for this increase in 

 oxygen consumption. His results agree for the most part with those 

 of current observations, except for showing an extraordinarily rapid 

 return to the basal level folio wing food. Fredericq's conclusions regard- 

 ing digestion represent a very great advance and deserve to be widely 

 quoted at the present time. His article gives one of the best considera- 

 tions of digestive activity ever written. 



Henrijean, 1883. Henrijean, 1 publishing from Fredericq's labora- 

 tory, and using his apparatus, made a study of the influence of alcohol 

 in nutrition. The experiments were made each morning at the same 

 hour and continued 15 minutes; 5 were fasting experiments, 4 after 

 alcohol, and 3 after food. In the food experiments bread varying in 

 amount from 120 to 190 grams was given. The results are expressed 

 as oxygen consumed in 15 minutes, reduced to standard conditions of 

 temperature and pressure. Thus during fast the oxygen consumption 

 was 3.5 liters, with alcohol 4.17 liters, and with bread 4.35 liters. From 

 these data Henrijean concludes that the amount of oxygen consumed 

 after alcohol or food in general is always greater than that when fasting ; 

 the increment after bread is approximately 25 per cent ; after alcohol 

 it is a little less. 



Jolyet, Bergonie, and Sigalas, 1887. Using a new respiration appa- 

 ratus on a closed-circuit plan, in which the subject breathes through a 

 hermetically sealed mask, Jolyet, Bergonie, and Sigalas 2 report two 

 series of experiments which have a slight bearing upon the question of 

 the influence of food. Thus, as an average of 7 experiments with the 

 subject fasting and at rest, they found the oxygen consumption per 

 kilogram per hour was 259 c.c. In 7 experiments with food (neither 

 the kinds nor the amounts of food are stated) the oxygen consumption 

 was 275 c.c. per kilogram per hour. Apparently no further experi- 

 ments were made on this problem with the apparatus. 



Lehmann, Mueller, Munk, Senator, and Zuntz, 1887-1893. The first 

 use of the Zuntz-Geppert respiration apparatus for studying the me- 

 tabolism of man was in the series of observations made on the fasting 

 subjects, Cetti and Breithaupt. 3 The study made with Cetti in March, 

 1887, was reported in brief by Senator and his collaborators. 4 This con- 

 sisted of a fasting period of 10 days, followed by 3 days with food. The 



Henrijean, Bulletin 1'Acad. Roy. de Belgique, 1883, ser. 3, 5, p. 113. 



2 Jolyet, Bergoni?, and Sigalas, Compt. rend., 1887, 105, pp. 380 and 675. 



3 Although the essentials of the Zuntz-Geppert apparatus were described by Zuntz and his asso- 

 ciates (Lehmann, Mueller, Munk, Senator, and Zuntz., Arch. f. path. Anat. u. Physiol., 

 1893, 131, Supp., p. 1), the best description of the apparatus was that given later by 

 Magnus-Levy, Arch. f. d. ges. Physiol., 1894, 55, p. 1. 



^Senator, Berl. klin. Wochenschr., 1887, Nr. 16, p. 290; Nr. 24, p. 425; see especially report 

 by Zuntz and Lehmann, p. 428. 



