13 
teen feet wide, and the plots composing the sets were, respec- 
the rays of the radium from reaching every plot on the tract and 
modifying its yield. 
ach plot of a series received exactly the same amount of 
the same kind of fertilizer, applied at the same time and in the 
same way. Every operation of seeding, hoeing, cultivating, 
etc., was performed across all five plots at once. Thus, if rain 
or other condition caused interruption, no plot would have any 
advantage or disadvantage eas to time over any other. In short, 
growth of plants in the five plots of a series, except as to the 
amount of R A F that was applied. 
In all but one case, the RAF was sowed equally over the 
surface and then dug in. In this one case, part of it was put in 
the rows, in order that a comparison of results might be obtained. 
When some of the early crops were harvested, the ground was 
again dug, and other crops planted. More fertilizer was then 
applied, but in no case was any more a AF 
in the soil was, however, much more ao eee by 
this nee digging. 
e 3-foot path was not sufficient to prevent the emana- 
tions aa crossing and affecting the adjoining plots is fully 
proved by the observations which follow. A 5 by 19 foot plot 
of turnips, not treated with radium, lying j h of treated 
— 25 Bouse : A Pt to oe acre hats Baying ae rows — 
h ro 
and, therefore, separated by only the 3-foot ne from the - 
pound plot, twice as large and strong as those at the northern 
€ g 
in the 25-pound plot, those at the southern ends of the rows, 
separated by 3 feet from the 50-pound plot, being twice as large 
