1887.] 



and its Relation to Putrefaction. 



455 



Experiments show that the rigidity is easily overcome (1) by 

 alternate flexion and extension ; (2) by raising the temperature ; 

 (3) by freezing; (4) by the action of acids and alkalies ; and (5) by 

 means of organisms. That this last cause is more important than 

 ail the others put together might, perhaps, be inferred from the 

 fact that in fish in which bacteria abound in the tissues at death, 

 either no rigor or a very weak one makes its appearance. This 

 inference is confirmed by the following observations and experi- 

 ments. (1.) A septic solution was injected into the right femoral 

 artery of a newly killed rabbit, the rigor, though it appeared about 

 the same time in the right limb as in the left, disappeared much 

 quicker from the right. (2.) A large roach was killed on the 4th 

 February and at once gutted. The muscles of the right side, imme- 

 diately in contact with the peritoneal lining, were inoculated by 

 septic bacteria (introduced by pricking the peritoneum with a rosette 

 of needles fixed in a piece of sealing-wax) and the peritoneum covering 

 the left side of the body-cavity was washed with a solution of 

 corrosive sublimate (1 in 10,000). The rigor was to my surprise 

 equally well marked on the two sides ; but 24 hours after death, 

 when the rigor began to disappear, the right side became limp about 

 2^ hours before the left, and 36 hours after death the muscles of the 

 right side were soft and beginning to putrefy, while those of the left 

 were still firm ; further, a piece of muscle taken from under the skin 

 of the right side opposite the anterior margin of the dorsal fin swarmed 

 with bacteria, while a piece of muscle from a corresponding point 

 on the left side contained comparatively few bacteria. (3.) Roach 

 and trout, which were gutted immediately after death, and dipped for 

 a time in solutions of phenol (5 per cent.) and corrosive sublimate 

 (1 in 1,000), and afterwards introduced into sterilised water, retained 

 their rigor unimpaired for an indefinite time. Whenever the fish, 

 however, were transferred from the sterilised into ordinary water, 

 rigor began to disappear — the passing off being always accelerated 

 when organisms were introduced into the water, or when the tempera- 

 ture was raised. Believing the rigor in the above fish might be 

 mere stiffening produced and maintained by the action of the phenol 

 and corrosive sublimate solutions, I introduced fish from which the 

 rigor had been driven off by heat into similar solutions of phenol 

 and corrosive sublimate. Limp fish treated in this way never became 

 stiff — the natural firmness of the fresh muscles was simply maintained. 

 (4.) Eels which were thrown into instantaneous rigor by strong 

 electric shocks behaved in the same way. The posterior half of a 

 large eel (the part behind the body-cavity) in cataleptic rigor was 

 placed in phenol and then in sterilised water on the 8th April. A 

 similar portion was introduced on the same day into sterilised water 

 after the skin had been rendered aseptic by corrosive sublimate. 



