INORGANIC FOODS. 357 



by the cells is an active process. Thus the cell withdraws from the serum, 

 which is rich in sodium salts and contains less potassium, the potassium. 

 It is possible that the researches of Bokorny l concerning the behavior of 

 lower organisms to solutions of certain dyestuffs may throw some light 

 on these processes. 



He showed, namely, that the protoplasm of certain cells would take up 

 definite compounds even from very dilute solutions, so that, for example, 

 a colored solution would eventually become colorless. Bokorny assumed 

 that chemical combination took place between the protoplasm and the 

 substances in question. He showed, for example, that the Spirogyra and 

 Cladophora would absorb silver from a solution containing only one part 

 in 100,000,000. In a solution of 1 : 10,000,000 enough silver was taken up 

 so that when treated with hydrochloric acid and hydrogen sulphide the 

 algae turned black. Likewise from very dilute solutions of copper and 

 mercury salts the cells would remove the inorganic material. Toward 

 other compounds, e.g. gold salts, the behavior was quite different. From 

 gold solutions containing one part in 100,000 the gold is not removed by 

 the above-mentioned algae, nor by yeast cells. There is a specific action 

 between these cells and the heavy metals which we cannot explain at 

 present. The absorption of certain salts by the cells of the animal organism 

 must take place in conjunction with certain definite and specific processes 

 by means of which a definite selection in definite proportions is made 

 possible. Quite recently we have become able to explain in a measure 

 the part played by salts in the life of the cells. The function of the salts 

 is undoubtedly chiefly an osmotic one. It is the task of the inorganic 

 salts to regulate the osmotic pressure of the cell-fluid itself and of the 

 intercellular fluid. It is clear that any change taking place in this pres- 

 sure, whether by the taking up or giving off of water, causing a swelling 

 or a shrinking of the cell, or, on the other hand, any changing in the 

 concentration or dilution of the reacting mixture contained in the proto- 

 plasma, will immediately lead to most serious disturbances in the 

 progress of certain reactions. Above all, the velocity of the reactions will 

 be changed. 



The part played by the inorganic material is not restricted, however, to 

 maintaining this constant osmotic pressure between the liquids within 

 and without the cell. This is evident from the fact that the cell requires 

 certain definite salts. It is not possible, for instance, to replace success- 

 fully the potassium in the cell by an equivalent amount of sodium. The 

 individual salts must exert for themselves a specific action, although it is 

 not yet clear as to just what this may be. We are acquainted with quite 

 a number of isolated facts in this connection, but with our present knowl- 

 edge it is not possible to group them together and view them from one 



Chem.-Ztg. 29, 1201 (1905). 



