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 .