1 6 PHYSICAL CHEMISTRY IN MEDICINE. 



fore not able to replace the salts which in dilute solution 

 are almost completely ionized. 



// is not the salts but the ions of the salts that are essen- 

 tial to the organism. 



Our belief that many reactions of living matter can 

 be traced back to the properties of the dead ground- 

 substance itself seems to be true not alone of the proteins 

 and their closely related bodies. 



EMIL FISCHER has been able to show, for example, that 

 the fact that enzymes or living organisms split certain 

 kinds of sugars more easily than others is dependent 

 upon their structural peculiarities, and has assumed the 

 existence of a peculiar, stereochemical relation between 

 the reacting substances. 



A remarkable similarity between the reactions in dead 

 and in living matter has also been proven to exist for the 

 fats. If we allow two immiscible liquids, such as oil 

 and water, to compete for a substance soluble in both, 

 the amounts of this substance dissolved in the two solvents 

 bear a definite proportion to each other. MEYER and 

 his pupil BAUM have studied a long series of narcotics 

 with reference to their distribution coefficient in the 

 above mixture, and have been able to point out a far- 

 reaching parallelism between the distribution coefficient 

 of a substance and its narcotic effect. This observation 

 has led MEYER to an interesting theory of narcosis, 

 based upon the difference in the distribution of the active 

 substances between the watery tissue fluids and the fat- 

 like constituents of nerve tissue. 



We will now leave the field of more or less indirect 

 biochemical investigation and, even though but hastily, 

 Consider the results which have been obtained through 



