9 
greatest on hank es and almost equally great on the petal 
tissues of the flow 
Against this array of positive evidence as to the stimulating 
effects of the radium, I had the negative effect of a caution from 
the French Agricultural Bureau against the anaes of such 
a pronounced action as had been reported, on the ground that 
the amounts of radium in radio-active earths which had een 
employed were so very small. Little weight c be given to 
in the experiments, it was a pure assumption that this activity is 
wholly due to radium, or that such radium is actually present in 
the top-soil, and in fact it seems far more probable that it is in 
part due to the direct effect of the sun upon the soil. However, 
the case was one that called preéminently for the actual test of 
experimentation and to this I applied myself in the most practical 
possible way. 
I made it my business, for the time being, to ignore all theoret- 
ical considerations and to proceed with my trials precisely as a 
farmer would proceed in aS the land and applying the 
radio-active material for a market 
My experiments and nee ie ide the winter culture 
of radishes in a market gardener’s greenhouse, some seedlings 
in window boxes in home; crops covering r 
than one hundred acres at Northfield, Ohio, under the direction 
r. ey: an experimental garden at Pittsburgh, 
The greenhouse radishes were already about an inch high 
when the radium was applied. A furrow was scratched midway 
between the rows, which were four inches apart, and the powder 
sowed therein at the rate of sixteen grains to the square foot, 
i 
radium radishes soon appeared much inferior to the others, ne 
