27 



sium acts on boiling triphenyl methane resulting in tbe development 

 of hydrogen, but that sodium does not; (3) that i)otassium salicylate is 

 converted at 210° C. into the isomeric paraoxybenzoate,^ while in the 

 sodium paraoxybenzoate just the reverse transformation is produced 

 at 300° 0. (Kolbe); (4) that potassium hydroxid decomposes peroxid 

 of hydrogen more quickly than does sodium hydroxid (Schone). 



It seems very probable to the writer that from the physiological point 

 of view the condensing properties of potassium are of prime impor- 

 tance. Substantial reasons exist for assuming chemical condensation 

 processes, not only in the formation of carbohydrates and fat, but also 

 in that of the proteins, i. e., in the three principal compounds of the 

 plant cell. The writer called attention to this probable role of potas- 

 sium salts in plants as early as 1880,^ and still holds this explanation 

 to be the correct one. 



It is very probable that for the condensing operations the organoids 

 of plant cells use a potassium protein compound. It is well known, of 

 course, that chloroplasts require potassium salts for the assimilatory 

 function and further that they have an alkaline reaction.^ Finally, there 

 can be no longer any doubt that sugars are produced by condensation. 



As regards the formation of protein, the writer has on various occa- 

 sions i)ointed out that certain facts, especially the great rapidity of 

 protein formation in many instances and the absence of by-products 

 and between-products, inevitably lead to the assumption that in this 

 process also condensation plays an important part. But potassium 

 salts are absolutely indispensable in animal life also, although the 

 synthetical work performed is not so far-reaching as in i)lants. How- 

 ever, the formation of fat from sugar in the animal body requires 

 condensation as well as reduction, while the formation of glycogen* 

 from glucose and that of proteids from proteoses consists in dehydra- 

 tion and polymerization. In sucb cases potassium salts may play 

 a role, and perhaps also in the processes of organization, as, for example, 

 in the leucocytes and gland cells, which latter are in certain cases fre- 

 quently renewed, or in the contractile substance of the muscles when 

 work or starvation have destroyed a part of it.^ 



^The corresponding rubidium salt in this case behaves similarly and therefore 

 bears more resemblance to the potassium than to the sodium salt. 



'■^Pfluger's Arch., Vol. XXII, p. 510. 



^'Molisch (Bot. Zeit., 1898, No. 2) observed that as soon as the cells are killed and 

 the chloroplasts come in direct contact with the acid cell sap, the cells of Coleus or 

 Perilla, rich in chloroplasts and containing anthocyan in an acid cell sap, under- 

 went the characteristic change from red to blue and green produced by alkaline 

 liquids. Cells of the same plants which are poor in chloroplasts or free from them 

 do not show this change. 



""The liver, which is the principal organ in glycogen formation, contains, according 

 to Oidtmann, three times more potassium than sodium, while in the spleen the pro- 

 portion is, according to the same author, just the reverse. 



^Organization, as it takes place in a developing organ, is one of the least-known 

 vital processes. One thing, however, is sure, that is, that a connection of numerous 

 protein molecules in groups of a higher order takes place. This connecting process 

 was supposed by Pfluger to consist in polymerization or etherification. 



