CONTENTS 9 



PAG 



Air we Breathe Changes in the Air from Respiration Changes 

 in the Blood Interchange of Gases in the Lungs Comparison 

 between Arterial and Venous Blood Respiratory Labor Im- 

 purities of the Air Dust Carbonic Acid Effects of Impure 

 Air Nature's Provision for Purifying the Air Ventilation 

 Animal Heat 187 



CHAPTER IX 



THE NERVOUS SYSTEM 



Animal and Vegetative Functions Sensation, Motion, and Volition 



The Structure of the Nervous System The White and Gray 

 Substances The Brain Its Convolutions The Cerebellum 



The Spinal Cord and its System of Nerves The Anterior 

 and Posterior Roots The Sympathetic System of Nerves The 

 Properties of Nervous Tissue Excitability of Nervous Tissues 

 The Functions of the Spinal Nerves and Cord The Direction 

 of the Fibres of the Cord Reflex Activity and its Uses 2 he 

 Functions of the Medulla Oblongata and the Cranial Ganglia r 

 The Reflex Action of the Brain Effects of Alcohol, Tobacco, 

 Snuff, Narcotics, Opium, Chloral, Hasheesh, Chloroform . . 217 



'CHAPTER X 



THE SPECIAL SENSES 



The Production of Sensations Variety of Sensations General 

 Sensibility Pain and its Function Special Sensation, Touch, 

 Taste, Smell, Sight, and Hearing The Hand, the Organ of 

 Touch The Sense of Touch Delicacy of Touch Sensation 

 of Temperature and Weight The Tongue, the Organ of Taste 



The Nerves of Taste The Sense of Taste, and its Relations 

 with the other Senses The Influence of Education on the Taste 



The Nasal Cavities, or the Organs of Smell The Olfactory 

 Nerve The Uses of the Sense of Smell The Sense of Sight 

 Light The Optic Nerve The Eyeball and its Coverings The 

 Function of the Iris The Sclerotic, Choroid, and Retina The 

 Tears and their Function The Movements of the Eyeball 

 The Function of Accommodation The Sense of Hearing and 

 Sound The Ear, or the Organ of Hearing The External, 

 Middle, and Internal Ear 264 



