REST AND ACTIVITY. 563 



oxygen can labor for some time and still yield carbon dioxide 



(HERMANN 1 ). 



During muscular inactivity, in the ordinary sense, a consumption 

 of glycogen takes place. This is inferred from the observations of several 

 investigators that the quantity of glycogen is increased and its correspond- 

 ing consumption reduced in those muscles whose chemical tonus is reduced 

 either by cutting through the nerve or for other reasons (BERNARD, 

 CHANDELON, VAY, 2 and others) . In activity this consumption of glyco- 

 gen is increased, and it has been positively proven by the researches of 

 several investigators (NASSE, WEISS, KULZ, MARCUSE, MANCHE, MORAT 

 and DUFOUR 3 ) that the quantity of glycogen in the muscles in activity 

 decreases quickly and freely. As shown by the researches of CHAUVEAU 

 and KAUFMANN, QUINQUAUD, MORAT and DUFOUR, CAVAZZANI, and 

 especially those of SEEGEN, 4 the sugar is removed from the blood and 

 consumed during activity. The recent investigations of JOH. MULLER, 

 LOCKE and ROSENHEIM and CAMIS 5 have given direct proof of the 

 consumption of sugar during muscular activity. In experiments on 

 surviving hearts of different animals through which was perfused a salt 

 solution containing sugar, they could detect an undoubted consumption 

 of sugar which was quite considerable and which to all appearances was 

 used as material for muscle work. 



The aniphoteric reaction of the inactive muscles is changed dur- 

 ing activity to an acid reaction (Du BOIS-REYMOND and others), and 

 the acid reaction increases, to a certain point, with the work. The quickly 

 contracting pale muscles produce, according to GLEISS, G more acid dur- 

 ing activity than the more slowly contracting red muscles. The acid 

 reaction appearing during activity was formerly considered to be due 

 to the formation of lactic acid, a view which has been contradicted by 

 ASTASCHEWSKY, PFLUGER, and WARREN, who found less lactic acid in 

 the tetanized muscle than when at rest. MONARI also found a decrease 

 in the quantity of lactic acid during activity, and according to HEFFTER 



1 1. c. In regard to gas exchange in removed muscles, see aso J. Tissot, Arch, de 

 Physiol. (5), 6 and 7, and Compt, rend., 120. 



2 Chandelon, Pfliiger's Arch., 13; Vay, Arch, f. exp. Path. u. Pharm., 34, which 

 also contains the pertinent literature. 



3 Nasse, Pfluger's Arch., 2; Weiss, Wien. Sitzungsber., 64; Kiilz, in Ludwig's 

 Festschrift, Marburg, 1890; Marcuse, Pfliiger's Arch., 39; Handle", Zeitschr. f. Biolo- 

 gic, 25; Morat and Dufour, Arch, de Physiol. (5), 4. 



4 Chauveau and Kaufmann, Compt. rend., 103, 104, and 105; Quinquaud, Maly's 

 Jahresber., 16; Morat and Dufour, 1. c.; Cavazzani, Centralbl. f. Physiol., 8; Seegen, 

 "Die Zuckerbildung im Thierkorper," Berlin, 1890, Centralbl. f. Physiol., 8, 9, and 

 10; Arch. f. (Anat. u.) Physiol., 1895 and 1896; Pfliiger's Arch., 50. 



5 Joh. Miiller, Zeitschr. f. allgem. Physiol., 3; Camis, ibid., 8; Locke and Rosen- 

 heim, Journ. of Physiol., 36. 



6 Pfluger's Arch., 41. 



