by the Roots of Living Plants. /. 169 
A pure strain of seed of each species was obtained from Messrs. Sutton 
and Sons. 
Methods. 
Seeds were germinated in sawdust watered with tap-water, and when 
the roots were two or three inches long the seedlings were transferred to 
a water-culture solution of the following composition (Crone ( 1 )) : 
KN 0 3 i*° grm. 
Ca(N 0 3 ) 2 0*2-5 g rm - 
MgS 0 4 0-25 grm. 
Fe,'(P 0 4 ) 2 0-5 grm. 
Distilled water up to 1,000 c.c. 
The plants were grown in this solution for about a fortnight in order to 
obtain healthy, uninjured roots. From these plants a number were selected 
which possessed, as far as could be judged, an approximately equal root 
development, and these were transferred to the calcium chloride solutions. 
Three concentrations of the salt were employed : 
N 
10 ’ 
N 
100 
and 
N 
1000 
the solutions being contained in wide-mouthed bottles of 1,200 to 1,3000.0. 
capacity, such as are generally used for water-culture experiments. Only 
one plant was grown in each bottle. The usual precautions necessary for 
growing plants in water-cultures were taken. After various times a number 
of plants were withdrawn from the experimental solutions. The following 
quantities were then determined in the solutions: (1) the concentration of 
calcium, (2) the concentration of chloride, (3) the electrical conductivity, 
(4) the hydrogen-ion concentration, (5) the presence of other metallic ions. 
The calcium was determined gravimetrically as calcium oxide, and the 
chloride volumetrically. In the case of the more dilute solutions a large 
bulk of solution was evaporated down for each determination. As a number 
of plants were removed from each solution at the same time, it was possible 
to calculate the probable error of the results. The electrical conductivity 
was measured in the ordinary way by Kohlrausch's method, and the 
hydrogen-ion concentration was determined colorimetrically. 
Experimental Results. 
Series 1. A number of plants of the edible pea were grown in the 
culture solution indicated in the preceding section, and groups of sixteen 
plants transferred to each of the three calcium chloride solutions : 
N N N 
10 100 1000 
o 2 
