I 



332 OF THE PRIMARY TISSUES OF THE HUMAN BODY. 



their fibres, without destroying their life ; for when thawed they showed the 

 same life which they had before : this is exactly similar to the freezing of blood 

 too fast for its coagulation, which, when thawed, does afterwards coagulate, as 

 it depends in each on the life of the part not being destroyed." 1 



333. The Rigor Mortis, or cadaveric stiffening of the muscles, is probably to 

 be regarded as the final manifestation of this property ; occurring after all the 

 Irritability of the muscles has departed, but before any putrefactive change has 

 commenced. The supervention of the rigidity is not usually prolonged much 

 beyond seven hours ; but twenty or even thirty hours may elapse, before it shows 

 itself. Its general duration is from twenty-four to thirty-six hours ; but it may 

 pass off much more rapidly ; or it may be prolonged through several days. It 

 first affects the neck and lower jaw, and seems gradually to travel downwards ; 

 but, according to some observers, the lower extremities are stiffened before the 

 upper. In its departure, which is immediately followed by decomposition, the 

 same order is observed. It affects all the muscles nearly alike ; but the flexors 

 are usually more contracted than the extensors, so that the fingers are somewhat 

 flexed on the palm, and the forearm on the arm ; and the lower jaw, if previ- 

 ously drooping, is commonly drawn firmly against the upper. It is remarkable 

 that it is equally intense in muscles which have been paralyzed by Hemiplegia, 

 provided that no considerable change has taken place in their nutrition. When 

 very strong, it renders the muscles prominent, as in voluntary contraction. 

 An attempt has been made to connect it with the lowering of the Temperature 

 of the dead body ; but with this it does not seem to have any relation, since it 

 has frequently been observed to commence long before the heat has entirely 

 departed from the body, and appears first upon the trunk, which is the region 

 last deserted by warmth. Another attempt has been made to show a correspond- 

 ence 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 is the 

 last act of its vitality ( 29), so the stiffening of the muscles is the expiring 

 effort of theirs. 3 



1 "General Principles of the Blood," in " Hunter's Works," (Palmer's Edition,) vol. iii. 

 p. 109. 



2 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 mus- 

 cular 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 con- 

 dition may give rise. The body of a man was found in a ditch, with the trunk and limbs 

 in such a relative position, as could only be maintained by the stiffness of the articulations. 

 This stiifness must have come on at the very moment when the body took that position ; 

 unless it could be imagined, that the body had been supported by the alleged murderers, 

 until the joints were locked by cadaveric stiifness. A post-mortem examination showed 

 that there was no necessity for this supposition obviously a very improbable one in itself 

 by affording sufficient evidence that apoplexy, resulting from the chronic disease, was the 

 cause of death. A case occurred a few years since in Scotland, in which the same pica 

 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 prisoner, that death had 

 been natural, and had resulted from fracture of the processus 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, 



