PHYSIOLOGIC APPARATUS 



755 



receives a glass shade, which covers the whole. The air of the chamber is 

 kept moist by placing in it pieces of blotting-paper saturated with water. 



From the under surface of the platform there descends a rod, which, by 

 means of a double binding screw, supports a horizontal rod, modified at one 

 end to carry the delicate axis of a light stiff recording lever. 

 lever is pointed, to enable it to write on a smoked glass or paper. Beneath 

 the axis is a strip of brass, carrying a screw, which gives support to the lever 

 until the instant the contraction of the muscle begins. This screw, ^tne 

 after-loading screw, also enables the lever to be placed ^OTi^talpoation. 

 The portion of the lever near the axis is provided with a double hook, tl 

 lower portion of which serves for the attachment of the weight by which tl 



no as in the registration of a muscle contraction under 



varying conditions, it is necessary to give the lever mass by attaching weights 



FIG. 350. MOIST CHAMBER. 





paper, . piece of tm.el 



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the 





