272 PHYSIOLOGICAL CHEMISTRY. 



strikingly the different amounts of water (independent of the 

 amount of fat) in the flesh of different animals. According to the 

 analyses of ALMEN, the muscles of lean oxen contain 15 p. m. fat 

 and 767 p. m. water; the flesh of the pike contains only 1.5 fat 

 and 839 p. m. water. 



For certain purposes, as, for example, for the tests of the exchange 

 of material, it is important to know the amount of nitrogen in the 

 flesh. In general, it may be considered on an average as about 3.4$ 

 of the fresh lean flesh (Vorr). According to NOWAK and HUPPERT 

 this quantity may vary about 0.6$, and in more exact investigations 

 it is therefore necessary to determine the nitrogen. 



Non-striated Muscles. 



The smooth muscles have a neutral or alkaline reaction (Du- 

 BOIS-KEYMOND) when at rest. During activity they are acid, 

 which is inferred from the observations of BERNSTEIN, who found 

 that the nearly continually contracting sphincter muscle of the 

 Anodonta is acid during life. The smooth muscles may also, 

 according to HEIDENHAIN and KUHNE, pass into rigor mortis and 

 thereby become acid. Because of this behavior it is believed that 

 among the albuminous bodies of the smooth muscles there is also a 

 substance forming myosin. A spontaneously coagulating plasma 

 has not thus far been obtained, but it may be considered as the juice 

 obtained by pressing the muscles of the Anodonta and which 

 coagulates immediately at + 45 C. or within 24 hours at the ordinary 

 temperature. Myosin has not been found in the smooth muscles. 

 HEIDENHAIN and HELLWIG have obtained from the smooth 

 muscles of a dog an albuminous body which coagulates at -j- 45- 

 49 C. and which is analogous to musculin. The smooth muscles 

 contain large amounts of alkali albuminates besides an albumin 

 coagulating at -{- 75 C. 



HcemogloUn occurs in the smooth muscles of certain animals, but 

 is absent in others. Creatin has been found by LEHMANN. Accord- 

 ing to FREMY and VALENCIENNES, the muscles of the Cepha- 

 lopods contain taurin besides creatinin (creatinf). Of the non- 

 nitrogenized substances, glycogen and lactic acid have been found 

 without doubt. The mineral constituents show the remarkable fact 

 that the sodium combinations exceed the potassium combinations. 



