1895.] On the Nature of Muscular Contraction. 



Fia. 1. 



421 



The string is now observed for some minutes at a tension of 25 or 

 50 grammes, and at a constant temperature, until no further change in 

 the position of the lever can be discerned. If we now close for some 

 seconds the circuit of the battery through the spiral, the lever rises. 

 Upon opening the circuit, it falls. The thermometer in the glass indi- 

 cates a hardly perceptible rise in temperature, or no rise at all. 



We see the doubly-refractive string of our model corresponds with 

 the doubly-refractive muscular particle, which we suppose to be the 

 seat of the force of contraction, and therefore may be called 

 " inotagma ; " the water in the glass represents the watery isotropic 

 substance round the inotagma, doing duty as refrigerant ; the spiral 

 wire supplies the place of the chemically active thermogenic mole- 

 cules ; the. closure of the galvanic circuit corresponds with the 

 process of the stimulation of the muscular element. 



The experiment may be simplified by heating in the air a string 

 previously made to swell by being dipped in hot water and then 

 soaked in concentrated glycerine. The movements will then take 

 place more quickly on account of the quicker heating and cooling. 

 Moreover, the experiment may be repeated almost as often as one 

 likes. If we fasten to the lever a little metallic hook, which when 



