568 



SCIENCE 



[Vol. LV, No. 1430 



discharge tubes during the past ten years but 

 that "it has been generally assumed that this 

 helium has in some way been occluded in the 

 bombarded material." True; we have a list 

 of no less than 37 papers, most of them pub- 

 lished in the years 1912 to 1915, engaged in 

 this inconclusive argument. In spite of the 

 application of the best experimental skill no 

 agreement was reached and Rutherford's con- 

 clusion is the general one. Yet there are some 

 of the final experiments, particularly those of 

 Collie, which challenge that conclusion and the 

 problem is still one of the most attractive and 

 important of recent times. Certainly it urges 

 conservatism and the most rigorous criticism, 

 yet not one of the papers shows that helium 

 can not be produced and all call for the appli- 

 cation of some entirely new method to the same 

 problem. That we have now accomplished. 



The second point is that a measure of the 

 energy produced by the atomic decomposition, 

 as predicted by modern theories of atomic 

 structure, would be "a much more deiinite and 

 much more delicate test of disintegration of the 

 heavy elements into helium than the spectro- 

 scope." This is a rare example of the prefer- 

 ence for theory over fact, though saved by the 

 use of the word "test" instead of "proof," and 

 the chemist will be slow to accept it. Our 

 work has not gone far enough to permit the 

 measurement of the energy evolved but the 

 latter is certainly not as large as would be ex- 

 pected from the energy liberated in the dis- 

 integration of radium. Yet lack of the the- 

 oretical energy does not explain away the 

 formation of a cubic centimeter of permanent 

 gas from half a milligram of tungsten wire, 

 though it demands careful scrutiny and, if con- 

 firmed, some explanation. Perhaps a lesser 

 energy content accompanies the greater sta- 

 bility of the permanent metals, for even among 

 the radioactive elements the violence of disin- 

 tegration varies inversely with the stability. 



Finally Sir Ernest points out that no helium 

 has been observed in X-ray tubes operating at 

 100,000 volts, where electron impacts are even 

 more violent than in our experiments. But the 

 quantity of energy impressed on the target is 

 here minute, the tube cui-rent being measured 

 in milliamperes or less, whereas it is the essence 

 of our method to introduce as much as a 



coulomb of electricity into the wire within 

 1/300, 000th of a second, or many millions of 

 times as much in terms of power. We suppose 

 that it is temperature as such, i. e., the high 

 velocity collisions of the atomic nuclei with 

 one another, that effects the atomic decomposi- 

 tion. 



"We appreciate and welcome the spirit of 

 Rutherford's criticisms. Indeed it is for the 

 purpose of eliciting such criticism and stimu- 

 lating the laboratory study by other investi- 

 gators that we are publishing our work in its 

 present preliminary foi"m. The importance of 

 the problem wan-ants it. 



The real question now raised concerns the 

 broadcasting of the results of scientific re- 

 searches bj' our publicity agencies. This is an 

 important function and science has suffered 

 from its neglect. Yet our experience shows 

 that it can be overdone, for here is a research 

 heralded as "transmutation" to millions of 

 newspaper readers in at least six countries : 

 it is not transmutation in any proper meaning 

 of that term, it is merely a preHminary report 

 by no means accepted by, or offered to, the 

 scientific world as conclusive, and it must still 

 wait months before it can be properly pub- 

 lished in the appropriate scientific journal for 

 the study of those who are competent to ap- 

 praise it. Meanwhile it is the duty of scientists 

 to urge prudence and conservative judgment, 

 as Sir Ernest Rutherford has done. Our pub- 

 licity problems are not solved when we have 

 increased the effectiveness of contact with the 

 press. 



Gerald L. Wendt 

 Chicago, Illinois 



SCIENTIFIC LITERATURE 



RECENT WORK ON SOIL ACIDITY AND 



PLANT DISTRIBUTION 



When three independent investigators, liv- 

 ing in different countries, and not knowing of 

 one another's activities, hit upon a similar 

 method of study and reach essentially the same 

 conclusions concerning a set of natural phe- 

 nomena, it is not unreasonable to infer that a 

 correct understanding of the relations has been 

 reached. For many years it has been cus- 

 tomary to regard soil acidity as having no par- 

 ticular bearing on the distribution of native 



