were the same. T h e leaders of the aggressors found that, in spite of heroic m e a s u r e s through planned e c o n o m y a n d technology» their economies w e r e t o o .small geographically a n d populationwi.se. I t w a s t h e stated intention of the aggressors t o form large economic u n i t s by c o n q u e s t and domination for tlieir own a d v a n t a g e in which those d o m i n a t e d would not s h a r e . Twice in one g e n e r a t i o n w e engaged in d e v a s t a t i n g w a r t o prevent a reorganization of h u m a n alTairs t h r o u g h the formation of large economic u n i t s to meet t h e d e m a n d s of t h e industrial a g e . W e did that n o t b e cause t h e over-all objective was w r o n g , b u t because t he m e t h o d for their a c c o m plishment violated our f u n d a m e n t a l d e termination t o resist d o m i n a t i o n a n d press u r e from sectional interests. T h e prewar organization of h u m a n affairs, falling far s h o r t of meeting t h e r e quirements of t h e industrial age, h a s a c c e n t u a t e d the traditional fear of political a n d economic domination. / I t has s t i m u lated a trend toward d o m i n a t i o n t o avoid being dominated. A reorganization of human aïïairs b y peaceful m e a n s is i m perative in order t o reduce t h e p r o b a b i l i t y of future world w a r s a n d t o preserve t h e principles and a c c o m p l i s h m e n t ? of w e s t ern civilization. Uniting
onomic domination by any one would be impossible. T h i s is no mild reorientation, b u t there a r e not as m a n y obstacles in the way of this suggestion as there were in the s u m m e r of 1939. G e r m a n y is already dismembered, and the incorporation of its people into a large economy composed of small and i n d e p e n d e n t s t a t e s would a u t o matically eliminate domination from t h a t source. We must not forget t h a t until 1870 t h e v a r i o u s states of G e r m a n y were antagonistic t o each other suid were only united on t h e basis of language b>r force a n d b y domination of Prussia: I t a l y has been a united country only since Garibtddi, a n d its p r e s e n t economy is even m o r e hopeless t h a n before the war. France a p p e a r s to offer the greatest problem. However, h e r internal political situation is even more restless t h a n before the war and
A H E distribution a n d concentration of b e t a - e m i t t i n g tracers present in a sample m a y now b e studied by a new method called tracer micrography. In this procedure, developed by L. EYIarton of the National B u r e a u of S t a n d a r d s a n d P . H. Abelson of the Carnegie I n s t i t u t i o n of Washington, the radiation given off b y a radioisotope within a sample m a t e r i a l is m a d e to form an image of t h e emitting surface b y m e a n s of a m a g n e t i c a r r a n g e m e n t which acts a s a lens to focus the b e t a emissions on a suitable recording surface, such as a p h o t o g r a p h i c plate. Initial experiments were conducted with gallium 67 since the particles it emits are of uniform speed, thus minimizing the effects of chromatic aberration. Gallium chloride, prepared by chemical separation from zinc, was bombarded, by h e a v y hydrogen nuclei in the cyclotron at Carnegie I n s t i t u t i o n , a n d the solution e v a p o r a t e d d r o p b y d r o p on a 0.25-incL t a n t a l u m disk. R a d i a t i o n e m i t t e d from the surface of the disk, upon passing t h r o u g h a magnetic lens consisting of a smalL iron-clad coil with Armco iron pole pieces, was brought to a focus on a photographic film a t a d i s t a n c e of a b o u t 3.5 inches. A n image of t h e t a n t a l u m disk showing radioactive areas was t h u s obtained. T o calibrate the i n s t r u m e n t , photographic film was replaced by a Geigcr counter, a n d the lens current necessary to produce a m a x i m u m n u m b e r of c o u n t s in
Eur-opc
2 5,
NO.
29
«
«
Setting
tlie
Example
Faith and confidence in our own way of life should provide the talent to make positive contributions toward helping others a d o p t and enjoy a like one for themselves. T h e people of the world d o not need money or food as much as they want help to help themselves. T h e y have sacrificed m u c h to win what freedom they have and would be willing to sacrifice more if t h e y were offered a well-considered plan with a fai*· chance to keep and develop it for the common welfare. As the successful chemist knows, given a well-thought-out and defined project with a reasonable avenue of a t t a c k , the impossible frequently becomes possible.
Tracer Micrography Developed
I n an attempt t o solve t h i s major world problem, we are faced with so m a n y o b stacles i t sce-ims a l m o s t impossible. T h e failure of great efforts i n t h e past t o form a U n i t e d States o f Europe is clearly before us, but in this effort a few h a v e n o t been discouraged. T o these the e n d o r s e m e n t of this over-all objective by W i n s t o n Churchill and. o t h e r recognized leaders h a s encouraged tinem t o c o n t i n u e their efforts. Perhaps some suggestions for consideration of a new approach m a y b e of i n t e r e s t , a n approach i n which t h e people of E u r o p e a r e presented w i t h a c o m p l e t e d o c u m e n t clearly stating th.e principles and c o n d i tions under which, it is proposed to form a union of economic intereste. Such a d o c u m e n t acceptable t o t h e majority c a n o n l y be prepared by a c o m p a r a t i v e l y s m a l l group of unbiased leaders of c o n s t r u c t i v e t h i n k i n g , motivated only b y consideration of the common g o o d . With such a d o c u m e n t presented to t h e people there Avould still r e m a i n a r e a l a n d justified fca:r b y those of the s m a l l e r states of exploitation a n d d o m i n a t i o n b y t h e larger states. It need b u t be recalled t h a t the last of t r i e original t h i r t e e n s t a t e s to join the Union w a s t h e s m a l l e s t — Rhode Island—because it feared d o m i n a t i o n by the Larger ones. T h e r e a r e m a n y small states i n E u r o p e even m o r e s k e p t i c a l . As a possible means of overcoming t h i s obstacle T I s u g g e s t t h a t i n the f o r m u lation of a large economic u n i t c o n s i d e r a t i o n might b e given t o limiting t h e size of s t a t e s constituting t h e u n i o n . If all of t h e states were l i m i t e d to t h e size of t h e present smaller countries, political or e c V O L U M E
her economy almost destroyed during the occupation.
Tracer micrographs a thin layer of
*
JULY
2 1,
unit time was determined for radiation of varying velocities. This established the focusing current for a given type of radiation. I n preliminary experiments with samples of different concentration and thickness of the radioactive layer, exposure times ranged from 2 to 12 hours according to the age and concentration of the sample and the numerical a p e r t u r e of t h e lens. It was found t h a t micrographs with good definition were obtained consistently when the layer was sufficiently t h i n to avoid considerable self-absorption. T h e best resolving power attained so far has been a b o u t 30 microns. T h e simplicity of this method, b o t h in a p p a r a t u s a n d technique, is one of its more i m p o r t a n t features. V a c u u m requirements a r e very m o d e r a t e since the mean free p a t h of t h e electrons is large in comparison with the a p p a r a t u s dimensions. Reduced exposure time and better resolution due to a reduction in spherical aberration are expected with the application of after-acceleration of t h e b e t a particles by means of a homogeneous electrostatic field. A further reason for after-acceleration is t h a t chromatic aberration, which is always present, even in sources emitting particles of uniform speed, c a n be m a r k edly decreased if t h e accelerating potential is a t least comparable in m a g n i t u d e to the energy of t h e primary emission.
showing the distribution sample material on the
1947
of radioactive surface of a
isotopes tantalum
within disk
2073
