JARVIS'S PRACTICAL PHYSIOLOGY. 



718. What is said of the strength of the back? What illustration? 



719. What is the best position of the spine for burdens on the head? 



720. How is the head carried most easily? Explain. 



721. What is said of the centre of gravity in carrying burdens? 

 Give illustrations. 



722. What farther illustrations? 

 723 Explain this farther. 



724. What is said of the grace of this attitude ? 



CHAPTER XIX. 



725. What is the best attitude for walking? Why? 



726. What for labor ? What illustration ? 



727. What other persons act best in this position? 



728. How is the lateral curvature of the spine induced ? 



729. How is the forward curvature produced ? Who are liable toil? 



730. Who are exposed to this curvature ? How ? 



731. How is the spine affected by the position of persons writing? 

 or reading ? 



732. What is Dr. Warrens' opinion? 



733. Why are boys less subject to curved spine than girls? 



734. How are the lungs affected by curved spine? 



735. 736. How is the spinal cord ? 



CHAPTER XX. 



737. What law of nature is almost universal? 



738. What disadvantages has night labor? Illustrate. 



739. What is the experience of milkmen and others who devote a 

 part of the night to their business? 



CHAPTER XXI. 



740. What natural indication does man need to follow? 



741. Can the quantity of sleep be fixed by a general rule ? 



742. What shows night to be the season of sleep? 



743. What is the uniform effect of loss of sleep ? 



744. Why does sleep require an increase of clothing? 



745. What are the conditions necessary for refreshing sleep ? 



746. Does the digestive process go on well in sleep? 



PART VII. 

 BRAIN AND NERVOUS SYSTEM. 



CHAPTER I. 



747. Describe the brain. 



748. Into what portions is the brain divided? 



749. What are the offices of the membranes which divide the brain 



750. What is the spinal cord, and its position ? 



36 



