30 JPHE REASON WHY : 



Then say not man's imperfect, Heaven in fault; 

 Say rather, man's as perfect as he ought ; 

 His knowledge measured to his state and place; 

 His time a moment, and a point his space." POPK. 



thus all the heat which would have been requisite for its conversion 

 into vapour is preserved, and affords additional nourishment to the 

 system. 



79. Wliy does fear cause ike cheeks to turn pale, while rage makes 

 them red ? 



Because, when persons are affected by fear, the respiration and the 

 afflux of arterial blood are diminished, and paleness of the skin con- 

 sequently ensues ; but when the passions are excited, respiration 

 and the afflux of arterial blood are increased, and a flushed state of 

 the cheeks follows. 



80. Why is u, pale cheek and blanched lip an indication of 



Because the lesser or greater number of globules present in the 

 blood is made known in the one case by the pallor of the cheek, 

 and in the other by its florid appearance. And as these red 

 globules are the carriers of oxygen, and consequently in a great 

 measure the exciters of vital action, it follows that the general state 

 of the health is necessarily regulated by the supply of these 

 important agents. 



81. Why is headache increased by a jit of coughing ? 

 Because expiration assists the heart in propelling the blood, and 



as the act of coughing considerably increases expiration, the flow of 

 blood to the brain is greatly augmented, and the consequent 

 distended state of the vessels adds to the aching of the head. 



82. What are the lungs? 



The two lungs are placed, on each side of the spine, in hollow 

 sjaces formed by the arching of the ribs. They may be compared 

 to large pieces of sponge, which alternately suck in and squeeze out 

 the blood of the body and the air of the surrounding atmosphere. 

 The air passes and re-passes by the same tubes. The air-tubes, com- 

 mencing with the wind-pipe, and branching off frequently in 

 different directions, become gradually smaller and more numerous, 

 until they terminate in miimtf expansions, which are the air-cells 



