PROPERTIES OF MUSCULAR FIBRE. 289 



An attempt has been made to show a correspondence^ between the rigor 

 mortis and the coagulation of the blood in the vessels ; and there is certainly 

 evidence enough to make it appear that some analogy exists between these 

 two actions, though they are far from being identical. After those forms of 

 death, in which the blood does not coagulate, or coagulates feebly, the rigidity 

 commonly manifests itself least ; but this is by no means an invariable rule. 

 It seems probable that, as the coagulation of the blood will be shown to be the 

 last act of its vitality, so the stiffening of the muscles is the expiring effort of 

 theirs. The property to which it is due, however, would appear to be of a 

 different character from ordinary irritability. This may be inferred from the 

 fact, that the rigidity does not ordinarily come on until after the contractility 

 has departed sometimes for a considerable period ; and also from the circum- 

 stance, observable in most cases of Asphyxia, that the rigidity is very decided 

 and prolonged, whilst the contractility is speedily lost. This property, to 

 which the name of Tonicity has been given, is probably the same as that 

 which partly occasions the retraction of the muscle when divided during life ; 

 the degree of this retraction being much greater than that seen in a muscle 

 which has been for some time dead. Moreover, this kind of tonic contraction 

 is more directly excited by heat than that which results from ordinary con- 

 tractility ; and it is not excited by galvanism or mechanical irritation, which so 

 powerfully act on the latter. It is interesting, moreover, to remark, that the 

 state of habitual preponderance during sleep, of the flexor over the extensor 

 muscles (which last are the stronger), is explicable by attributing it to the 

 same property ; the manifestations of which thus correspond, whether the con- 

 tractility of the muscles be in a dormant or unexcited state, or whether it have 

 altogether departed from the tissue. 



391. It is necessary to bear in mind, when the phenomena of cadaveric 

 rigidity are brought into question in juridical investigations, that a state at 

 first sight corresponding to it may supervene immediately upon death, from 

 some peculiar condition of the nervous and muscular systems at the moment. 

 This has been observed in some cases of Asphyxia ; but chiefly when death 

 has resulted from apoplexy following chronic ramollissement of the brain or 

 spinal cord. This contraction, which is obviously of a tetanic character, 

 ceases after a few hours, and is then succeeded by a state of flexibility, after 

 which the ordinary rigidity supervenes. The following case illustrates the 

 nature of the inquiries, to which this condition may give rise.* The body of 

 a man was found 1 in a ditch, with the trunk and limbs in such a relative posi- 

 tion, as could only be maintained by the stiffness of the articulations. This 

 stiffness must have come on at the very moment when the body took that posi- 

 tion ; unless it could be imagined that the body had been supported by the 

 alleged murderers, until the joints were locked by cadaveric stiffness. A 

 post-mortem explanation showed, that there was no necessity for this supposi- 

 tion, obviously a very improbable one in itself; by affording sufficient evi- 

 dence that apoplexy, resulting from chronic disease, was the cause of death. 

 A case occurred a few years since in Scotland, in which the same plea was 

 raised. The body was found in a position in which it could have only been 

 retained by rigidity of the joints ; and it was pleaded, on the part of the pri- 

 soner, that death had been natural, and had resulted from fracture of the pro- 

 cessus dentatus, causing sudden pressure upon the spinal cord, whence the 

 spasmodic rigidity would naturally result. Proof was deficient, however, as 

 to the existence of this lesion before death ; and the position of the body rather 

 resembled that into which it might have been forced during the rigidity, than 

 that in which it would probably have been at the moment of death. There 



* Annales d'Hygiene, torn. vii. 

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