PART 111 



I 'll YHoUiCY OK .MoYK. \1K.\T 



/. MUSCLE rHYSIOLOGY 



In the following experiments the catalo-ue of the Iltirvard 

 Apparatus Company is to he used as an apparatus reference hook. 

 .Moi\- detailed explanations of the apparatus than can he given in 

 the laboratory direction sheets, will he found there. From now on 

 dissecting instruments will always be needed. 



STRIATED MUSCLE 

 \. MKTIK )1)S ( n-' STIMULATK >X. 



The apparatus used in electrical stimulation .should he carefuly 

 studicd in all details before the preparation of a frog's muscle for 

 experiment. 



173. Batteries. Observe the dry cell. Carbon (-f-) and zinc 

 (--) plates are immersed in a ma-- of porous clay permeated with 

 -trong XI I ,C1 solution. Attach wires to the binding po-t- of the bat- 

 tery and apply the ends of the wires to neutral litmus paper moistened 

 with XaCl solution. ( L'se insulated platinum-tipped wire-, i 

 Xote (a) reaction at -f~ ail( l ' poles ; (b) rapidity with which 

 color change a]t])ears with poles i i ) close together and (2) one 

 cm. apart. ( 3 ) several cm. apart. Kxplain this. What is ( )hm's law? 



174. Ap|)ly the ends of the wires as in the former experiment to 

 filter paper moistened with starch solution containing KI. Result? 

 At which pole doe- a reaction appear? Kxplain Repeat, varying 

 the di-tance between the two electrodes | anode (positive) and 

 cat hi >dc I negative I | . 



175. I )ip the end- of the platinum-tipped wires into weak acid so- 

 lution. What gase- are evolved and at which poles.' Try Xal 1 -olu- 

 li M. distilled \\ater and -ugar s, .hitii HIS. Results? 1 ; n>m the above 

 e.\]>eriments formulate a rule for distinguishing anode and cathode 

 in an unknown circuit. 



17''. Connect the cell in circuit with a simple key. Xow without 

 closing the circuit place the platinum electrodes on the tip of the 



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