CHEMICAL ELEMENTS 19 



shall have done my fellow man a good service by 

 pointing the way to hope and happiness. 



Sec. 3. Chemical Elements Composing the 



Human Body 



"Of the elements known to chemists," says Pro- 

 fessor Martin, ''only sixteen have been found to take 

 part in the formation of the human body. These are 

 (1) calcium, (2) carbon, (3) chlorine, (4) fluorine, 

 (5) hydrogen, (6) iron, (7) lithium, (8) magnesium, 

 (9) manganese, (10) nitrogen, (11) oxygen, (12) 

 phosphorus, (13) potassium, (14) silicon, (15) sodi- 

 um, and (16) sulphur. Copper and lead have some- 

 times been found in small quantities, but are probab- 

 ly accidental and occasional. (Martin, Human Body, 



p. 7.) 



It is clear that neither the nature nor the prop- 

 erties of these elementary substances, are changed by 

 the fact that such substance has become a part of the 

 body. For example, iron is iron whether in or out of 

 the body. 



It is probable that the chemical composition of 

 the human body is substantially the same as that of 

 the body of every other mammal. 



