PART II. EXPERIMENTAL PHYSIOLOGY. 



Instruments, &c., to be provided by each Student. Befoi -a 

 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 small scalpel ; a blunt needle or " seeker " in a handle ; 

 pins ; fine silk thread ; watch-glasses ; narrow glass rod drawn 

 out at one end to act as a " seeker " ; 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 XXV. 

 GALVANIC BATTERIES AND GALVANOSCOPE. 



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

 handle (fig. 80), and containing a saturated 

 solution of copper sulphate. Crystals of copper 

 sulphate are placed in it to keep the solution 

 saturated. The pot is about 18 cm. high, and 

 9 cm. in diameter. In the copper solution is 

 placed a roll of sheet-copper, provided with a 

 binding screw. Within is. a porous unglazed 

 cylindrical cell containing 10 p.c. solution of 

 sulphuric acid. A well amalgamated rod of 

 zinc, provided at its free end with a bind- 

 ing screw, is immersed in the acid. The zinc 

 is the negative pole or Cathode ( - ), and the copper the positive 

 pole or Anode ( + ). 



