John A. Leer makers, Eastman Koilak Co.: Glenn T. Seaborg, of California; Kenneth C. D. Hickman, Distil lotion Products,
plishments, both in t h e field of radioactive isotopes and in t h e chemistry of t h e transuranium elements, are impressive. H i s work a n d that of his colleagues were essential t o the development of t h e most i m p o r t a n t scientific work of our time in directions which society judges best. "Professor Seaborg cannot be held a c countable for w h a t society does with t h e results of his work, b u t he has n o t been unaware of its impact on social a n d political questions. H e has been quite active in discussing such questions a n d was a member of the executive committee of t h e Atomic Scientists of Chicago from t h e time of i t s formation." Describing t h e search for fissionable transuranium elements in nature, which was undertaken before the success of t h e nuclear chain reaction was assured, D r . Seaborg revealed t h a t the amount of plutonium found in pitchblende corresponds to about one p a r t in 1014, far too small t o serve as a practical source of this element for use a s a source of energy. A mechanism for its continuous formation from t h e spontaneous fission of U238 was described. F u r t h e r search for transuranium elements in radioactive ores by C. S. Garner, N . A. Bonner, a n d Seaborg revealed t h e presence of Pu 239 in carnotite in a b o u t t h e same concentration. The -work in this direction was t h e n discontinued, b u t it w a s concluded that transuranium elements do n o t exist in practical amounts on the face of the earth. T h e r e will, said Dr. Seaborg, be some neptunium, b u t its concentration will be smaller t h a n that of plutonium, and the a m o u n t s of americium a n d curium would appear t o IXJ oven smaller. " H o w ever, t h e r e is j u s t an outside possibility t h a t t h e r e might exist some transuranium isotope o r isotopes as yet unknown a n d formed b y a mechanism as yet n o t conceived."
Univ. Inc.
Seaborg Discusses Transuranium Elements in Howe Lecture A STAFF
X H K isolation of a pure compound of americium in weighable amounts a n d t h e natural occurrence of plutonium in caraotite were announced by Glenn T. Seaborg at t h e second annual Harrison Howe Lecture of the Rochester Section of t h e AMEIUCAK CHEMICAL SOCIETY on Nov. 18.
Dr. Seaborg, who is professor in t h e College of Chemistry and director of chemistry in t h e Radiation Laboratory a t t h e University of California, revealed t h a t B. B . Cunningham, working at t h e Metallurgical Laboratory, University of Chicago, h a s succeeded in isolating pure americium hydroxide in weighable amounts and in studying its chemical properties on t h e ultramierochemical scale. I n liis lecture, "Plutonium a n d Other Transuranium Elements", in which he discussed t h e chemical and radioactive properties of t h e known transuranium elements, neptunium, plutonium, americium, and curium, t h e latter three of which he was codiscoverer, D r . Seaborg predicted t h a t neptunium may eventually become a familiar element in university laboratories b u t t h a t the high alpha-activity of t h e other transuranium elements will make i t necessary to handle them in small amounts and in special laboratories; the extreme activity of curium introduces still further difficulties such as the decomposition of water a n d recoil due to alpha-emission. T h e lecture, second in t h e series founded by the Rochester Section t o commemorate the services of the late Harrison E . Howe
REPORT
briefly about D r . Howe who was a founder a n d officer of t h e Rochester Section before he became editor of Industrial and Engineering Chemistry and CHEMICAL AND EN- Cm 2 1 2 4- n
•is also formed as t h e result of the strung neutron irradiation of Am 211 , announced Dr. Seaborg. Am 241 absorbs neutrons to form a short half-lived ( I S hours) betaemitter, Am 2 * 2 , which in turn decays to Cm2"12. T h e clement curium has not yet been isolated in t h e p u r e s t a t e , and its tremendous alpha a c t i v i t y will m a k e it difficult to handle i n the laboratory. In addition to health factors, there will be difficulties such as the decomposition of water of solution, formation of hydrogen peroxide, heating, and other effects introduced by the high rate of alpha emission. T h e isotope Cm 242 w i t h its five-month half life (that of C m 2 4 0 is one m o n t h ) has a specific
E. H. Taylor, secreE€istman Kodak Co.
alpha-activity corresponding to a b o u t 10 14 alpha disintegrations per milligram per minute, a n d the aggregate recoil of s u b microgram particles keeps it in constant motion and soon spreads a n y appreciable concent ration, of t h e element over a wide area. Once this pure element is available in microgram amounts, it will be possible to study its chemistry on t h e ultramicrochemical scale although each measurement will be most difficult and laborious. It is, of course, concluded Dr. Seaborg, not improbable t h a t i t wilt eventually b e possible t o prepare isotopes of curium of longer half-life. " I t is, in fact, even p r o b able t h a t isotopes such a s Cm 244 , Cm 24 *, or Cm 216 m a y have longer half-lives arid t h a t these isotopes may eventually become available for investigation." Following t h e lecture, Dr. Seaborg showed color slides made b y Life magazine of scenes in t h e Metallurgical L a b o r a t o r y a t the University of Chicago. The complete text of Dr. Seaborg's talk will b e published a t a later d a t e .
llCTfl T- Seaborg topes.^wheia he joined .the'Metallurgical As codiscoverer of three ^elements,, jjLaborators?;j> of the ,/University- of ;;Jphicago.i3i;1942, - ^ e r a v X . Seaborg , Seaborg lxblds'a unique 'distinction for * 1 this late day. r contributed' significantly to the de^^yelo^^enfe^f l'tmcer^ and, ultraxntcro* : ^, B o m on April 19, 1912, at Ishpe-,~ ^fc^eKu^I^^y^gties fer studying the * ;ining, 'Mich., Seaborg was graduated -' /cHero^^ ,of:which' he \' (A:B. 1934)\from the ^University: of/\ ^i^^^s^v&^y^3&' group ^ was' the - - California-at I;os Angeles:aiid obtained-: ^ ''tib^eh.D. a V B e r k e l e ^ j m ^ a r . ' ^oifr::y ' 4 S f t f c ^ 5 ^ ) a i e r / a , visible^ quantity of v ; ^ I | t o ^ j g D | ^ a n d < o n ; the/>asis; of ttheir•\\ - ^lo^rihg;two years as rese^cli 5 ^sociafe;'. c ^ ^ £ $ ^ ^ S | m i B * s t i 6 e * ^ c e W ^ r * plu-^ ^V^witff G.JST. Lewis, he r6^;f^^ly*feoW/*', * linstruetpr iric 1939 :to}:MtZpt0^or^m^ f$|io»iu^^ • V^i&&' * at;\Caiifornia ^ t o ^ ^ J H c ^ h e V ; ^ ^ ^ v > *4 ^fiwBomW workmen ;tae chenjofetry* of^ri^SS^waH^iig^ i?eiAjgrned!^iErozzi.v l e a y e 5 a t ^ | | p giisiaaranium ^ —--ui-i—a ^i4puiifi^
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