206 PHYSIOLOGY. 



most machines. While energy may fail to be used for the 

 desired purpose, it is never destroyed nor really lost. 



CORRELATION AND CONSERVATION OF ENERGY. 



1. The Correlation of Energy. All kinds of energy 

 are so related to one another that energy of any kind can 

 be transformed into energy of any other kind. 



2. The Conservation of Energy. When one form of 

 energy disappears, an exact equivalent of another form 

 of energy always takes its place, so that the sum total of 

 energy is unchanged. 



These two principles constitute the corner stone of phys- 

 ical science, and must be learned and kept in mind if we 

 would understand the actions of our bodies, and our rela- 

 tions to the surrounding parts of the world and the universe 

 in which we live and of which we must consider ourselves 

 a part. 



READING. Foods and Dietaries, Burnet ; Diet in Rela- 

 tion to Age and Activity, Thompson. 



Summary. i . The blood flow is a true circulation ; that is, the 

 blood moves in a circuit, being more or less altered by every organ it 

 passes through. 



2. The body is an eddy into which particles are constantly entering, 

 forming part of it a while, and then passing out. 



3. Fat as tissue is stored food, and consequently stored energy. 



4. Glycogen is a carbohydrate reserve stored temporarily in the 

 liver. 



5. Nutrition includes all the processes of the body from the time 

 matter enters as food until it leaves as waste matter. 



6. The building-up processes of the body are called Anabolism, the 

 tearing down are Katabolism, and both of these are included under 

 Metabolism. 



