648 Waring ton.— The Effect of Boric Acid and Borax on 
an increase in the green weight might have been realized. (The fresh 
weight of plants in water culture is difficult to determine with any accuracy, 
owing to the wet condition of the roots.) These plants also seemed to be 
less mature than the controls, the boron possibly exerting some retarding 
effect. Consequently, if the plants had been harvested at a later stage, some 
increase in the dry weight might reasonably have been expected to be shown. 
Should this suggestion be justifiable, the slight indication of stimulation 
which was obtained in the preliminary experiment, where the plants were 
•3 
•2 
•1 
0 
TeXT-FIG. 4. Barley grown in water-culture solution containing different quantities of boric acid. 
Feb. 21-May 24, 1921 (average of five plants) : - Dry Weight;--—• per cent. Nitrogen ; 
------ Actual N. 
not harvested until in ear, may possibly be of real import. However, the 
evidence is too incomplete for any definite conclusions to be drawn. The 
difference between plants treated with equivalent amounts of boric acid and 
borax is not significant, but on the whole the borax-treated plants gave 
a slightly higher dry weight figure than the corresponding sets treated with 
boric acid. 
shoot 
No definite relationship was shown between the - ratios of the 
root 
variously treated barley plants, as was noticed in the case of the broad bean. 
It would seem, therefore, that in the case of barley the root and shoot are 
affected more or less equally by the boron compound. 
