RESUMÉ 



By the investigations nuuic by Beckki? and Oi.skn, („Metabolism during Mental 

 Work", Skandinavisches Archiv lur Physiologie, vol. 31), there was shown a con- 

 siderable increase of the CA)., eliminated during mental work; and it was pointed 

 out that only part of this CO, was likely to be attributable to a dilution of the CO., 

 stored in the organism. The two above-mentioned experimenters, however, did not 

 succeed in deciding, how great a quantity might be attributed to the work done 

 simultaneously. The present experiments were consequently made to have this 

 question of doubt replied to, using practically the same apparatus and methods as 

 the aforesaid authors. By these measurements were decided not only the CO., eli- 

 minated, but also the 0., absorbed; and at the same time an attempt was made to 

 measure, by means of control-experiments, how great a quantity of the increased 

 metabolism might issue from the increased respiration, caused by the work. The 

 purpose of this was if possible to decide to what extent the central nervous system 

 was accountable for the changes of metabolism obtained. — However, this proved 

 impossible as varying and often considerable changes of the muscular tone inthien- 

 ced the metabolism, and neither directly nor indirectly could be done away with. 

 From these measurements appears as follows : 



The same sort of work will involve approximately constant changes of meta- 

 bolism as regards the same subject. No constant proportion exists, however, be- 

 tween the increase of the absorbed and the CO.^ eliminated ; a relatively small 

 value of the former may frequently be connected with a relatively big value of the 

 latter, and vice versa. The 0,^ values show most frecjuently, but by no means always, 

 smaller variations than the CO.^ values. 



Ditïerent classes of work will, as regards the same subject, involve the bigger 

 changes of metabolism the more strenuous the work in question is. These diflerences 

 can be very great and are equally conspicuous in the CO., as well as in the O., values. 



The same work may involve most various changes of metabolism as regards 

 different subjects, which is only a natural consequence of the fact, that the meta- 

 bolism grows with the strain. If a person has more practice in or talent for a 



