igoo-i.] Effects of Water on Foliage Leaves. 271 



the advantage of the plant. (For illustration of the method used to 

 supply the leaves with food see Fig. 7). It was found expedient to 

 paint the bottles in which the roots were immersed, with black bicycle 

 enamel to protect the roots from the light. 



Series I. 



The first of the following series of experiments was begun on October 

 13th, 1899, and carried on at the physiological laboratory at the botanic 

 gardens, and is the first of the series to test whether a nutrient solution 

 can be made to support the life of a plant by applying it to the leaves in 

 the form of a spray. The roots were placed in distilled sterilized water 

 and the supply was kept up by means of a system of tubes arranged for 

 the purpose. The corks of the bottles were smeared with a specially 

 prepared soft wax, and above this was placed a piece of sheet rubber, 

 cut so as to go round the stem of the plant in the form of a hollow cone, 

 then cemented in this position so as to shed the liquid used as a spray, 

 and to keep as much as possible of the spray from coming into contact 

 with the wax. The wax served the purpose of doubly securing the 

 liquid at the roots from contamination with the liquid used as a spray. 

 (See Fig. 7). 



Plants used — Thunbergia alata. 



Plant A. — Roots in distilled water and leaves fed by a spray of 

 nutrient solution (Fig. 7). 



Plant B I. — In distilled water but no spray. 



Plant B 2. — Under same condition as B i. 



Plant B J. — Roots in distilled water, plant under jar and 

 moistened daily. 



Plant C. — Control, in flower-pot in soil. 



The records of growth in length are for the purpose of inquiring into 

 the manner in which the growth is affected when the plant is placed 

 under these conditions. Measurements are o-iven in millimeters. 



