NECROSIS OF TISSUES. 11 



exertion, mechanical violence, and chemical agents, and most 

 rapidly of all, by means of distilled Avater. 



Nmnerons researches, the latest and most exhaustive of which 

 we owe to TT". Kiiluie {I. c), render it certain that this rigidity 

 of the muscular fibres is immediately due to the precipitation of a 

 solid albuminous constituent from the muscular fluid. This muscle 

 clot (myosin of Kiilme) forms a white and not very transparent 

 mass, and so causes marked opalescence of those muscles which 

 are in a state of rigor mortis, complicated, moreover, by a shade 

 of brown. 



^ow, although rigor mortis is the first step towards death, 

 it is a step which is not irretrievable. It is quite possible to 

 throw a fro2;'s leo' into a state of rigor mortis bv tyincr the 

 afferent vessels, and then to watch it resume its normal condition 

 on removal of the ligature. Should the case be one of per- 

 manent death of the muscular fibre, the rigidity is followed by 

 decomposition. The naked-eye phenomena of this farther change 

 are, first, the fading of the bright red colour of the muscular 

 tissue, which is rej^laced by a dirty red, or yellowish grey tint, 

 unless it happen to be saturated Avith dissolved ha^matin ;. 

 secondly, the cohesion of the muscle is impaired to such an 

 extent that it finally becomes converted either into a greasy, 

 jelly-like mass, in Avhicli no trace of its former fibrous structure 

 can be detected, or into an easily torn, dirty grey, tindery sub- 

 stance, in wdiicli some indications of longitudinal striation are 

 still to be found. The microscopic appearances are even more 

 constant. The transverse stride and nuclei are masked by a 

 cloud of minute dark specks ; oil globules, and granules of 

 reddish pigment appear partly within, partly outside, of the con- 

 tractile substance ; the latter is torn across at intervals ; the 

 framnents melt aw\ay from their edo-es to their centre ; the sarco- 

 lemma holds out longest, and when it finally succumbs to the 

 common fate, it contains only a few small, shapeless fragments 

 of its former contents, which mingle with the rest of the cUbris 

 (%. 1, c).- 



* Fall' states {Gentralhlatf, 1866, p. 434) that the transverse strire 

 approach nearer to each other before they are swallowed up in the cloud 

 of grannies, and that the complete solution of the fibres is not infre- 

 quently preceded by a longitudinal splitting of the contractile substance. 



