x CONTENTS. 



The Chemistry of Muscle. 



PAGE 



58. Contrast of living and dead muscle; rigor mortis .... 95 

 59. Chemical bodies present in dead muscle ; niyosin, syntonin . . 96 

 60. Chemistry of living muscle; muscle-plasma, muscle-clot and muscle- 

 serum, myoglobulin, histo-hasmatin 98 



61. Acid reaction of rigid muscle; development of carbonic acid in rigor 



mortis . 99 



62. Other constituents of muscle 101 



63. Chemical changes during contraction ; development of carbonic acid 



and acid reaction 102 



64. Summary of the chemistry of muscle ....... 104 



Thermal Changes. 



65. Heat given out during a contraction. Comparison of muscle with a 



stearn engine 104 



Electrical Changes. 



66. Non-polarisable electrodes. Muscle currents; their distribution and 



nature 106 



67. Negative variation of the muscle current; currents of action. The 



rheoscopic frog Ill 



The Changes in a Nerve during the passage of a Nervous Impiilse. 



68. Structure of a nerve. Primitive sheath or neurilernma, medulla, axis 



cylinder, nodes of Eanvier. The axis cylinder the essential part 113 

 69. Nerve endings in striated muscular fibres. Henle's sheath. End- 

 plates 118 



70. Non-medullated nerve fibres 120 



71. The chemistry of a nerve; cholesteriu, lecithin, cerebrin, protagon . 121 

 72. The nervous impulse; the electrical changes accompanying it. These 



changes travel in both directions along the nerve . . . 123 

 73. Summary of the changes occurring in a muscle and nerve as the 



result of stimulation . . . 125 



SECTION III. 



THE NATURE OF THE CHANGES THROUGH WHICH AN ELECTRIC CURRENT 

 IS ABLE TO GENERATE A NERVOUS IMPULSE. 



Action of the Constant Current. 



74. Action of the constant current; making and breaking contractions . 126 

 75. Electrotonus. Effect of the constant current on the irritability of 



the nerve. Katelectrotonus. -Anelectrotonus .... 128 



76. Electrotouic currents .......... 130 



77. Relation of electrotonus to nervous impulses, and to the effects of 



the constant current 132 



78. Action of the constant current on muscle 134 



