126 life's beginning on the earth 



gum of plant origin. If this is injected in a suitable solution 

 into the veins of patients with edema due to kidney disease, 

 the edema is markedly relieved, as one might expect. This 

 treatment has only recently been adopted and seems to be 

 quite promising. 



Again we see that one of those phases of life that we can 

 imitate in the laboratory, osmosis, plays an important role 

 even in the function of an organism as highly specialized as 

 the human body. 



8. THE ARTIFICIAL OSMOTIC STRUCTURE 



Every serious student of vital processes feels keenly the 

 difficulties under which he struggles in his study of life. 

 Abundant evidence is available to demonstrate evolution 

 in the living world. But since we cannot perform experi- 

 ments which require millions of years, we are at a loss to 

 demonstrate experimentally just what the process of evo- 

 lution was. 



Attempts to reveal the origin of life, are also handicapped, 

 this time by our incomplete knowledge of chemistry. Al- 

 though 300,000 compounds of carbon have been made, the 

 chemical make-up of the most important substances of the 

 living world, the enzymes, is shrouded in mystery. 



As to the role of salt and water, we can observe the ex- 

 panding forces, which they produce, through the osmotic 

 pressure in Traube's simple bag-like artificial cell; but such 

 a make-shift rivals in no way the complexity of the living 

 cell. Yet there are simple means of using the osmotic 

 forces to yield something which has a I least a remote re- 

 semblance to plants and animals. 



Without preliminary explanations, here is a description 

 of a practical method of obtaining more life-like structures 

 through osmotic growth: we take a 1 per cent solution of 

 copper sulfate (a salt) and place in it a solid crystal of yellow 

 prussiate of potash (a sail known in chemistry as potassium 



