Aug., 192o.] THE NITROGEN INDUSTRY. 20 9 ~CCONNEI.L, R. E.: " The Production of Nitrogenous Compounds Syntheti- cally in the United States and Germany," 1919 . " Metallurgical and Chemical Engineering," I9Ig-I920. " Nitrate Supply Committee Recommendations on Synthetic Nitric Acid for the Government, with Reports on Various Methods," 1917. PARSONS, C . L . : " Commercial Oxidation of Ammonia to Nitric Acid," 1919. " The Journal of Industrial and Engneering Chemistry," I918-I92o. Various newspaper articles. Various reports from Naval Attach6s, foreign publications, and other confiden- tial and secret reports on file in the office of the Director of Naval Intelli- gence, Navy Department. \VHtTE, A. H. : " The Present Status of Nitrogen Fixation," 19r 9. " Work of the British Nitrogen Products Committee," I918. The Mass-spectra of Chemical Elements. F. W. ASTON. (Phil. Mag., May, I920.)--The Positive Ray Spectrograph is de- scribed in detail by means of which a focussed spectrum is obtained. The lines due to the joint action of a magnetic and of an electric field are located in positions which depend only on the ratio of mass to electrical charge. The following elements have been analyzed: H, He, C, N, O, Ne, C1, A, Kr, X, Hg. Of these the first five seem to be pure, while the others are apparently made up of isotopes, varying in number from two in the case of argon to six for krypton. With the exception of hydrogen " all masses measured, allowing for multiple charges, are exactly whole numbers within the error of experiment (o--- 16)." While there is no reason to doubt the accuracy of the measurements, it is possible to interpret them in a somewhat different manner, as, indeed, a Philadelphia investigator does in the case of the atomic weight of argon. The prevalence of whole numbers is a fact of great sig- nificance for the understanding of the structure of the atom. To explain the failure of hydrogen to have a whole number for its mass, its mass proving by measurement to be i.oo8, the author reminds us that, on the electromagnetic theory of mass, the mass of an aggregate of masses is not in general equal to the sum of the component masses except when these are relatively far apart. 111 the nucleus of oxygen the packing of particles and electrons is close. Hence the atomic mass of the latter element is not sixteen times as great as that of hydrogen, but a little less than sixteen. GI F. S. New Process for Preparation of Glycerol,--During war glycerol is required' in abnormally large quantities for the manufac- ture Of munitions. Since fats and oils are the source o,f glycerol the supply Of these foodstuffs is consequently decreased; for the fatty acids, which may be obtained as a by-product in t~he manu- facture:of glycerol, cannot be directly ingested and assimilated.

The mass-spectra of chemical elements

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Page 1: The mass-spectra of chemical elements

Aug., 192o.] T H E NITROGEN INDUSTRY. 20 9

~CCONNEI.L, R. E.: " The Production of Nitrogenous Compounds Syntheti- cally in the United States and Germany," 1919 .

" Metallurgical and Chemical Engineering," I9Ig-I920. " Nitrate Supply Committee Recommendations on Synthetic Nitric Acid for

the Government, with Reports on Various Methods," 1917. PARSONS, C.L . : " Commercial Oxidation of Ammonia to Nitric Acid," 1919. " The Journal of Industrial and Engneering Chemistry," I918-I92o. Various newspaper articles. Various reports from Naval Attach6s, foreign publications, and other confiden-

tial and secret reports on file in the office of the Director of Naval Intelli- gence, Navy Department.

\VHtTE, A. H. : " The Present Status of Nitrogen Fixation," 19r 9. " Work of the British Nitrogen Products Committee," I918.

The Mass-spectra of Chemical Elements. F. W. ASTON. (Phil. Mag., May, I 9 2 0 . ) - - T h e P o s i t i v e R a y S p e c t r o g r a p h is de- s c r i b e d in de t a i l b y m e a n s of w h i c h a f o c u s s e d s p e c t r u m is ob- t a ined . T h e l ines due to the j o i n t ac t ion of a m a g n e t i c and of an e l ec t r i c f ield are l o c a t e d in p o s i t i o n s w h i c h d e p e n d on ly on the r a t i o of m a s s to e l ec t r i ca l cha rge . T h e f o l l o w i n g e l e m e n t s have been a n a l y z e d : H , He , C, N, O, Ne, C1, A, Kr , X, H g . Of t hese the f i rs t five seem to be pure , wh i l e the o t h e r s a re a p p a r e n t l y m a d e up of i so topes , v a r y i n g in n u m b e r f rom t w o in t he case of a r g o n to s ix for k r y p t o n . W i t h the e x c e p t i o n of h y d r o g e n " all m a s s e s m e a s u r e d , a l l o w i n g for m u l t i p l e c h a r g e s , a re e x a c t l y w h o l e n u m - be r s w i t h i n the e r ro r of e x p e r i m e n t ( o - - - 16) ." W h i l e there is no r e a s o n to d o u b t the a c c u r a c y of t he m e a s u r e m e n t s , i t is p o s s i b l e to i n t e r p r e t t h e m in a s o m e w h a t d i f f e r en t m a n n e r , as, indeed , a P h i l a d e l p h i a i n v e s t i g a t o r does in the case of the a t o m i c w e i g h t of a rgon . T h e p r e v a l e n c e of w h o l e n u m b e r s is a fac t of g r e a t s ig- n i f icance for the u n d e r s t a n d i n g of the s t r u c t u r e of t h e a tom. T o e x p l a i n the f a i lu re of h y d r o g e n to have a w h o l e n u m b e r for i ts mass , i t s m a s s p r o v i n g b y m e a s u r e m e n t to be i .oo8, the au thor r e m i n d s us tha t , on the e l e c t r o m a g n e t i c t h e o r y of mass , the m a s s of an a g g r e g a t e of m a s s e s is no t in g e n e r a l equa l to t he s u m of the component masses except when these are re la t ive ly far apar t . 111 the n u c l e u s of o x y g e n the p a c k i n g of p a r t i c l e s and e l e c t r o n s is close. H e n c e the a t o m i c m a s s of the l a t t e r e l e m e n t is no t s i x t e e n t i m e s as g r e a t as t h a t of h y d r o g e n , b u t a l i t t l e less t han s ix teen .

GI F . S.

N e w P r o c e s s for P r e p a r a t i o n of G l y c e r o l , - - D u r i n g w a r g l y c - erol is r equ i red ' in a b n o r m a l l y l a r g e q u a n t i t i e s fo r the m a n u f a c - t u r e Of m u n i t i o n s . S ince fa t s a n d oi ls a r e t h e sou rce o,f g l y c e r o l the s u p p l y Of t h e s e f o o d s t u f f s i s c o n s e q u e n t l y d e c r e a s e d ; fo r the

f a t t y ac ids , w h i c h m a y be o b t a i n e d as a b y - p r o d u c t in t~he m a n u - f a c t u r e : o f g l y c e r o l , c a n n o t be d i r e c t l y i n g e s t e d and a s s i m i l a t e d .