PART I). EXPERIMENTAL PHYSIOLOGY. 



Before beginning the experimental part of the course, each student 

 must provide himself with the following : A large and a small 

 pair of scissors ; a large and a fine pointed pair of forceps ; a 

 scalpel; a blunt needle or "seeker" in a handle; pins ; fine 

 silk thread ; bees' -wax ; sealing wax ; two camel' s-hair brushes 

 of medium size. It is convenient to have them all arranged in 

 a small case. 



PHYSIOLOGY OF MUSCLE AND NERVE. 



LESSON XXII. 



GALVANIC BATTERIES 

 GALVANOSCOPE. 



AND 



1. Daniell's Cell consists of a glazed earthenware pot with a 

 handle (Fig. 33) and containing a saturated solution of cupric 

 sulphate. Some crystals of cupric sulphate are placed in it to 



keep the solution saturated. The pot 

 itself is about 18 cm. high, and 9 cm. in 

 diameter. In the copper solution is placed 

 a roll of sheet-copper, provided with a 

 tongue, to which a binding screw is 

 attached. Within is a porous unglazed 

 cylindrical cell containing 10 per cent, 

 solution of sulphuric acid. A well amal- 

 gamated rod of zinc provided at its free 

 end with a binding screw is immersed in 

 the acid. The zinc is the negative ( - ), 

 Fig. 33. Daniell's Cell. and the copper the positive ( + ) pole. 



2. Amalgamation of the Zinc. The zinc should always be 

 well amalgamated. When a cell hisses, the zinc requires 



