PHYSIOLOGY AS A SUBJECT OF GENERAL EDUCATION 485 



Respiration : 



The respiratory system offers great opportunity for simple experimenta- 

 tion. Breathe on a sheet of cool glass to show that the expired air is saturated 

 with moisture, and breathe through lime water to show that a living 

 organism excretes carbon dioxide. Have the ' tough guy ' of the class 

 show off his chest expansion by means of cyrtometer tracings — two bits of 

 gas piping joined with rubber tubing are quite adequate. The rate of 

 respiration before and after exercise is instructive, and the period of 

 voluntary apnoea, first of all after deep breathing and then after exercise, 

 gives much material for teaching. And it has a vital reality for human 

 beings which all talk about fishes* gills totally lacks. 



Nervous System : 



The nervous system, unexpectedly perhaps, gives a wider scope for 

 elementary practical work than any other. Simple reflexes, such as the 

 knee jerk and the Achilles tendon jerk, are good material, so also are the eye 

 reflexes. The senses, too, offer good opportunities for practical work. 

 In the skin there are the senses of touch, pain and temperature, the ear and 

 labyrinth give opportunities for the physiologist and the physicist, while 

 there are a whole host of practical exercises in connection with the eyes. 

 I am thinking of the horizontal field of vision with one and with both eyes — 

 a string, a piece of chalk, coloured papers, and a bench top suffice. There 

 is the existence of the blind spot to demonstrate, the facts of visual acuity, 

 stereoscopic vision and various simple optical illusions. Why should 

 children be taught more about flies' eyes than about their own, more about 

 the spectrum than about colour vision ? Work with the senses, too, tends 

 to correct the crude and unthinking materialism which a study of chemistry 

 and physics, and even of conventional biology, is so apt to inculcate. 



This, then, is my thesis. For man, the rational approach to biology is 

 through study of human physiology. It imparts a foundation of knowledge 

 absolutely essential for every citizen of a democracy, it is good science, 

 good biology, and is admirably adapted to school instruction. 



Dr. L. P. LocKHART. — Physiology as a part of general education. 



This contribution to the discussion (for summary of which see p. 412) 

 has appeared in full in Lancet, 2, 1 177, 1937. 



