COMPOSITION OF THE MUSCLES. 571 



The quantity of water in the muscle is liable to considerable variation. 

 The quantity of fat has a special influence on the quantity of water, and 

 one finds, as a rule, that the flesh which is deficient in water is correspond- 

 ingly rich in fat. The quantity of water does not depend upon the amount 

 of fat alone, but upon many other circumstances, among which must 

 be mentioned the age of the animal. In young animals, the organs in 

 general, and therefore also the muscles, are poorer in solids and richer 

 in water. In man the quantity of water decreases until mature age, 

 but increases again toward old age. Work and .rest also influence 

 the quantity of water, for the active muscle contains more water than 

 the inactive. The uninterruptedly active heart should therefore be the 

 muscle richest in water. That the quantity of water may vary inde- 

 pendently of the amount of fat is strikingly shown by comparing the 

 muscles of different species of animals. In cold-blooded animals the 

 muscles generally have a greater quantity of water, in birds a lower. 

 The comparison of the flesh of cattle and fish shows very strikingly the 

 different amounts of water (independent of the quantity of fat) in the 

 flesh of different animals. According to the analysis of ALMEN 1 the 

 muscles of lean oxen contain 15 p. m. fat and 767 p. m. water; the flesh 

 of the pike contains only 1.5 p. m. fat and 839 p. m. water. 



For certain purposes, as, for example, in experiments on metabolism, 

 it is important to know the elementary composition of flesh. In regard 

 to the quantity of nitrogen we generally accept VOIT'S figure, namely, 

 3.4 per cent, as an average for fresh lean meat. According to NOWAK 

 and HuppERT 2 this quantity may vary about 0.6 per cent, and in more 

 exact investigations it is therefore necessary to specially determine 

 the nitrogen. Complete elementary analyses of flesh have been made 

 with great care by ARGUTINSKY. The average for ox-flesh dried in 

 vacuo and free from fat and with the glycogen deducted was as follows: 

 C 49.6; H 6.9; N 15.3; O + S 23.0; and ash 5.2 per cent. KOHLER 

 found as an average for water and fat-free beef C 49.86; H 6.78; N 15.68; 

 O + S 22.3 per cent, which are very similar results. This investigator 

 also made similar analyses of the flesh of various animals and deter- 

 mined the calorific value of the ash- and fat -free dried meat substance. 

 This value was, per gram of substance, 5599-5677 cal. The relation of 

 the carbon to nitrogen, which ARGUTINSKY calls the " flssh quotient," 

 is on an average 3.24:1. From KOHLER'S analyses the average for 

 beef is 3.15:1 and for horse-flesh 3.38:1. MAX MULLER has shown with 

 experiments on dogs, that the flesh of the same individual shows some 



1 Nova Act. Reg. Soc. Sclent. Upsal., Vol. extr. ord., 1877; also Maly's Jahresber., 7. 



2 Voit, Zeitschr. f. Biologie, 1; Huppert, ibid , 7; Nowak, Wien. Sitzungsber., 64, 

 Abt. 2. 



