142 



Prof. H. Marshall Ward. Effect of Mineral [Xov. 4, 



from the loose sand in water and the roots washed and displayed on 

 black paper (fig. 2) ; while in fig. 3 are appended other representative 

 specimens, similarly carefully extracted and washed and displayed 

 with the roots on black paper, and the shoots on white paper, 



"Fig. 1. — Specimen from Experiment 47 (Table I), photographed 4i days after 

 sowing, showing differences in stature and breadth of leaf. The plants in A 

 had received distilled water only; in B nutritive solution minus phosphorus; 

 in E no nitrogen ; in K no magnesia, and with five drops of ferric chloride ; 

 in N normal mineral solution with iron salts. L had no nitrogen, but five 

 drops of iron solution. 



The facts recorded in this table and in the legend to these figures 

 speak for themselves, but the following details may be noted. 



The effects of the deficiency of all salts (A) of phosphorus (B) and 

 of nitrogen (E) are distinctly observable in the poor development of 

 the roots, as well as of the feeble and narrow leaves j but although 

 the opposite effects of the rich manurial action of the horse-dung 

 decoction (0) and the normal mineral solution (G) are plain, the 

 differential results of the solutions minus calcium and potassium are 

 by no means obvious, nor did the addition of the five drops of dilute 

 ferric chloride seem to make much difference. 



Apart from an error in regard to the calcium (c, Table I), I attribute 

 this to the circumstance that it is extremely difficult to starve such 



