a 
THE HARMFUL ACTION OF DISTILLED WATER 259 
During this period, the Ca content varied between 10.37 parts 
(May, 1904) and 5441 parts per million (Dec, 1904); the Mg content 
between 1.87 parts (May, 1904) and 8.29 parts (Dec, 1904); the K 
content between a "trace" during 9 months of the period and 5 parts 
per million in June, 1904. 
The beakers containing the cultures, when not under observation, 
were shut in a dark laboratory cupboard, where the temperature was 
maintained between 20° and 22.5° C. 
Owing to the limits set on the development of lupine roots by 
distilled water, extended experiments could not be carried out. It is 
clear, therefore, that the behavior of plants during long periods should 
be investigated with peas, maize, or other species which are less sensi- 
tive to the influences exerted by distilled water. 
Effect of Using Condensers Made of Different Materials 
It was thought desirable, first of all, to establish the relation 
between the growth rate in Potomac water and in distilled waters 
made by using condensers of various materials. Accordingly, water 
was distilled from glass, the vapors being condensed in copper, tin, 
platinum and glass condensers, respectively. The resulting waters 
were tested in two different experiments, the following summary 
presenting the average of the two series of plants : 
Table I 
Waters Condensed in Different Materials 
Temp. 20° to 22.5° C. 
Growth ist Growth 2d 
Source of water 24 hrs., mm. 24 hrs., mm. 
Copper Condenser 14.5 6.2 
Tin Condenser 15,7 6.5 
Platinum Condenser . 18.2 6.7 
Glass 16.2 6.5 
Potomac water 23.5 27.5 
From this experiment it is clear that all distilled waters were 
distinctly harmful in their action during the first 24-hour period, the 
advantage being wi h the platinum condenser. According to Nageli 
(9), Loew (8) and others, glass apparatus is supposed to deliver 
physiologically safe distilled water. It is of interest in this connection 
to note that Copeland and Kahlenberg (34) found that lupine roots 
