356 MUSCLES. 



The power of elongation or relaxation seems to be an active 

 state of the muscle, as well as its contraction. This power of 

 relaxation or of elongation is much inferior to that of contrac- 

 tion; it seems to be only what is sufficient to restore the mus- 

 cle to its proper length, so as to put it in a condition for the 

 renewal of its contractions. The fixedness of muscles, which 

 are contracted spasmodically, and their retaining this position 

 even after death, until putrefaction begins to assail them, show 

 that the power of elongation does not depend simply upon 

 elasticity; for the latter quality being as much the attribute of 

 dead as of living matter, would be brought into play on death. 



The fixation of muscles is not a distinct power, but merely 

 a qualification of contraction, by which the latter may be ar- 

 rested at any given point, and retained there. 



As every muscle augments in thickness during its contrac- 

 tion, it has been a subject of inquiry to physiologists whether 

 the whole mass of muscle was increased or diminished by its 

 contraction. Swammerdam, in order to ascertain it, put an 

 insulated solid muscle, not yet dead, into a tube filled with wa- 

 ter; by irritating the muscle, and causing it to contract, the 

 water descended; but this result was not uniform. When an 

 arm is plunged into a tube properly formed and filled with wa- 

 ter, if the muscles be caused to contract, the fluid descends; 

 but the objection to the inference from this experiment is, that 

 when all the muscles of the arm are caused to contract vio- 

 lently, the introduction of arterial blood is much arrested, if 

 not fully stopped; and the venous blood is at the same time ex- 

 pelled : so that the change in the size of the member may be 

 accounted for in that way. The experiments of Erman on eels, 

 fully immersed in a fluid, and submitted to Galvanic influence, 

 are said to substantiate the theory cf the muscles diminishing 

 in bulk by contracting.* 



The activity of a muscle, though closely depending upon the 

 afflux of blood to it, is not entirely so; for it is ascertained that 

 Galvanism will cause the muscles of frogs to contract, when 

 the circulation is arrested by death, or when the blood is co- 

 agulated, or even when it has been drawn off.t This pheno- 



* Beclard; loe. cit. 



t Prochasku dc Carne Muscular!. Vienne, 1778. 



