350 



WATER FROM THE ROOTS OF THE RED MALLEE, 



Results of analyses of Red Mallee root-water and of soil-solu- 

 tion, in parts per 100,000: — ■ 



Potash (K.,0) 



Soda (Na.,0) 



Lime (CaO) 



Magnesia (MgO) ... 



Chlorine (CI) 



Sulphuric anhydride (SO.) 

 Phosphoric oxide (P 2 6 ) 

 Undetermined and loss ... 



Less oxygen equivalent to chlorine 



Total salts 

 Organic matter ... 



Total solids 



Specific gravity... 1.0003 10007 



• Chiefly tannin. 



In the root-water analysis, the carbon dioxide present in the ash, 

 being' produced during incineration, is extraneous, and has been 

 deducted. The chlorine was determined in the water direct. The 

 sample was insufficient to enable me to investigate the nature of 

 the tannin, of which the organic matter mainly consisted. 



Unfortunately, the American report does not take cognisance 

 of soda, chlorine or sulphuric anhydride. The organic matter in 

 the soil water would probably consist principally of humus. Taking 

 the figures for soil solution as being representative, it is interesting 

 to note how the plant has selected the substances absorbed. Thus 

 potash and lime are taken up in greater relative proportion than 

 magnesia. This selective action is well known. A striking illus- 

 tration is furnished by marine plants, which, though bathed in a 

 medium containing enormous relative proportions of soda and 

 magnesia, take up very little of these substances, but select the 

 much less abundant potash. Although land-plants do possess a 

 very decided power of selection, we have evidence that this is to 



