22 



very rich in potassium salts will absorb almost uo soda. The amount 

 of potassa annually required per hectare of i)ine forest is about 7.5 

 kilos, of wheat field 37.5 kilos, of clover field 102 kilos, and of potato 

 field 125 kilos. Other things being equal, an iDcrease of potassa will 

 increase to a certain degree the percentage of carbohydrates, and 

 further, potassa is reported to be present in larger proportions in those 

 I)arts in which the carbohydrates are transported, as in the parenchyma 

 of the bark and i)ith. 



Secondary potassium phosphate possibly forms loose combinations 

 with proteins more easily than does sodium phosphate, since an increase 

 of potassium phosphate is generally accompanied by an increase of 

 proteins, as in the seeds. Pollen grains also seem^o be rich in this salt; 

 at least Eamann found that of the ash in the pine pollen 50.74 per cent 

 was potassa and 30.08 per cent i)hosphoric acid. Seeds always contain 

 much more potassium phosphate than sodium phosphate, while on the 

 other hand the proportion of soda to potassa in form of other salts 

 than phosphates is often found to be larger in the leaves and roots.^ 



The following table shows the composition of seeds of Graminese and 

 Leguminosse, the latter containing, as is known, relatively more protein 

 than the former : 



Analysis of the seeds of Graminea and Leguminosce.* 



Product analyzed. 



Number j Total ash. 

 analyses. M^^^^^Se. 



Average In 100 

 parts of ash. 



Soda, i Potassa. 



Protein. 



Gramineae : 

 Wheat 

 Rye... 

 Barley. 

 Maize . 

 Oats... 

 Millet . 



Average . 



Leguminosas : 



Vetch , 



Pea 



Lupin 



Soy bean 



Field bean ( Vieia) 



Garden bean (Phaseolus) . 



Average . 



Per cent. Per cent. Per cent. ; Per cent. 



20 ! 

 .50 



1.97 

 2.09 

 2.60 

 1.51 

 3.14 

 3.43 



2.457 



3.23 



2.25 

 1.70 

 2.53 

 1.83 

 2.34 

 1.30 



2.17 



31.16 

 31.47 

 20.15 

 27.93 

 16.32 

 11.39 



23.07 



).21 



11.0 

 10.3 

 10.1 

 10.0 



10.2 



! 

 3 1 



3.10 



7.86 



30.14 



27.9 



29 ' 



2.73 \ 



0.96 



41.79 



22.7 



^ I 



3.95 



0.37 



29.84 



35.3 



1 



2.83 ; 



1.08 



47.00 



33.2 



15 ! 



3.57 1 



1.34 



42.49 



24.8 



13 



3.22 ' 



1.49 



44.01 



24.3 



* These figures ^svere taken from E. Wolffs Aschen Analysen, Vol. I. 



Calculating from the above data the amount of soda and potassa for 

 1,000 parts of dry organic matter, the seeds of Graminese contain 0.48 

 part soda and 5.67 parts potassa, while those of Leguminosa^ contain 

 0.70 part soda and 12.66 parts potassa. It is seen, therefore, that there 



' lu some cases the amount of soda found in the leaves exceeds even that of potassa. 

 Wolff's tables give for the leaf of Daucus carota a total ash content of 13.53 per cent 

 for the dry matter, and for 100 parts of this ash 19.83 parts soda, bnt only 11.26 parts 

 of potassa. The occasionally rather large soda content in the leaves is due to the 

 current of transpiration, containing sodium salts among other things. 



