734 



SCIENCE 



[N. S. Vol. XLI. No. 1063 



from the corn grown on Series 200 in 1913, 

 the average results are considered trustworthy. 



EFFECT OF RADIUM ON FIELD CROPS 



Increase or Decrease per Acre 



Series 600 possesses an unusually satisfac- 

 tory degree of uniformity; but on Series 200 

 there are some topographic variations which 

 influence the rapidity of " run-off " or absorp- 

 tion of rain, and in very dry seasons, with 

 occasional dashing showers, when moisture is 

 a factor of great importance, these variations 

 appear in the crop yields. From April 11 to 

 September 11, a period of five months, the total 

 rainfall in 1913 was only 5.87 inches. Under 

 these adverse conditions, even the average re- 

 sults from Series 200 are not consideredi 

 trustworthy, notwithstanding the large num- 

 ber of separate trials making the averages. 

 Even from the general averages .01 milligram 

 of radium appears to have decreased the yield 

 by 1 bushel on the west part and to have made 

 2.3 bushels increase on the east part of the 

 field. Again, increasing the cost of radium 

 from $1 to $10 per acre appears to have in- 

 creased the yield of corn by 3.6 bushels on the 

 west part and by only .7 bushel on the east 

 part; and the further increase of $90 shows 

 apparent gains of 1.3 bushels on the west and 

 .5 bushel on the east part of this field. Of 

 course no conclusions should be drawn from 

 such discordant plus and minus results. 



The results with soy beans on Series 200 in 

 1914 agree within narrow limits in showing no 

 benefit from the radium applied the year be- 

 fore, the west half of the field giving slightly 



smaller and the east half slightly larger aver- 

 age yield where radium was added than on the 

 check plots. 



On Series 600 the average yields of corn in 

 1913 were slightly larger with two kernels per 

 hill and slightly smaller with three kernels per 

 hill where radium was applied, but the appar- 

 ent gains and losses are all well within the 

 experimental error of plot variation, and the 

 general average indicates no effect from the 

 radium. The yields of soy-bean seed on the 

 north half of this field in 1914 likewise reveal 

 no influence of radium, all rates of application 

 indicating as an average slight decreases for 

 radium on the west side and slight increases 

 on the east side of the field. With the soy- 

 bean hay the six general averages show no 

 effect from radium, four results being slightly 

 below the checks and the other two slightly 

 above. 



Thus from the two years' work we have six 

 trustworthy average results with corn, three 

 "for" and three "against" radium, and we 

 have eighteen averages with soy beans, nine 

 " for " and nine " against " radium. In all of 

 these trials the average variation from the 

 phecks is so slight and so evenly distributed, 

 "for" and "against," as to lead only to the 

 conclusion that radium applied at a cost of $1, 

 $10 or $100 per acre has produced no effect 

 upon the crop yields either the first or second 

 season. 



Eadium, with all its wonderful energy, is 

 found upon careful analysis of the known 

 facts, to afford no foundation for reasonable 

 expectation of increased crop yields, when 

 financial possibilities are considered. The rate 

 of application mentioned by Fabre, on the basis 

 of IJ microcuries for each space four inches 

 square and eight inches high, would cost about 

 $58,800 per acre at present prices for radium. 



It is true that the total ultimate energy 

 developed in 1,760 years from 1 pound of 

 radium wiU be equivalent to 35,000 horse-power 

 days of 24 hours each; but when the time i3 

 reduced to 100 days of good crop-growing 

 weather, and the amount of radium reduced 

 to 10 milligrams, or to a cost of $1,000 per 

 acre, then the energy emitted from the radium 



