8 



LIVING AND LIFELESS MATTER 



In the ash he found sodium, potassium, iron, magnesium, 

 calcium, phosphoric acid and chlorine. Since then a great 

 variety of different substances have been obtained from cells 

 and tissues of different living things some of which are given 

 in the following classification of the proteins: 

 CLASSIFICATION OF THE PROTEINS 



The above list does not give anything like a complete 

 enumeration of the chemical compounds which make up 

 protoplasm. Most of the above are merely compounds of 

 C, H, N, O, and P and vary in the relative percentages of 

 the different elements in combination. In the list only the 

 derivatives of the purine bases are given, but each of the 

 others includes a similar list of substances. Add to these 

 many compounds the various combinations of carbohy- 

 drates and fats, and the minerals Ca, Na, Fe, Mg, etc., and 

 some faint conception may be gained of the enormous 

 number of chemical bodies to be found in protoplasm. 



