THE CELL AND PROTOPLASM. 77 



more complex than any other known. It was for 

 a long time looked upon by many as a single 

 definite chemical compound, and attempts were 

 made to determine its chemical formula. Such 

 an analysis indicated a molecule made up of sev- 

 eral hundred atoms. Chemists did not, however, 

 look with much confidence upon these results, 

 and it is not surprising that there was no very close 

 agreement among them as to the number of atoms 

 in this supposed complex molecule. Moreover, 

 from the very first, some biologists thought pro- 

 toplasm to be not one, but more likely a mixture 

 of several substances. But although it was more 

 complex than any other substance studied, its 

 general characters were so like those of albumen 

 that it was uniformly regarded as a proteid; but 

 one which was of a higher complexity than others, 

 forming perhaps the highest number of a series 

 of complex chemical compounds, of which ordinary 

 proteids, such as albumen, formed lower mem- 

 bers. Thus, within a few years following the dis- 

 covery of protoplasm there had developed a theory 

 that living phenomena are due to the activities of 

 a definite though complex chemical compound, 

 composed chiefly of the elements carbon, oxygen, 

 hydrogen, and nitrogen, and closely related to 

 ordinary proteids. This substance was the basis 

 of living activity, and to its modification under 

 different conditions were due the miscellaneous 

 phenomena of life. 



(c) Significance of Protoplasm. The philosophi- 

 cal significance of this conception was very far- 

 reaching. The problem of life was was so simpli- 

 fied by substituting the simple protoplasm for the 

 complex organism that its solution seemed to be 

 not very difficult. This idea of a chemical com- 



