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ADJUSTABLE SPEED *
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SpasikUu ELECTRIC STIRRER THE ANALYST'S COLUMN
Range 200 to 1,400 Revolutions Per Minute
Speed Stabilized by Governor L.T.HALLETT, Science Editor· r .i.-4..r r . 1? ..*...|.^... î ^„.l„| vi _^. 1 .i„> - i,. Î ^... } „.Î^. 1 4„j.
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NON-SPARKING INDUCTION TYPE MOTOR Eliminates Explosion Hazard
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Ρ Η Ε three-day invitation symposium on trace analysis, initiated b y J o h n Yoe a n d held a t t h e New York Academy of Medicine, N o v e m b e r 2, 3 , a n d 4, w a s well organized, a n d t h e 22 m a i n speakers covered as m a n y different techniques as are used in trace analysis (see page 32 A of t h e September issue for list of topics). Of these speakers, four were from E u r o p e or E n g l a n d , so t h a t a good rep resentation a n d discussion of foreign development gave t h e symposium a n international aspect. T h e r e should be more of these, because d o c u m e n t a t i o n of foreign research, a l t h o u g h a d e q u a t e , does n o t stimulate thinking t h e same way as personal contact. I t was regret table t h a t t h e b a n q u e t speaker, Hedley M a r s t o n of Australia, a n d Professor Feigl found it impossible t o a t t e n d , b u t when a r r a n g e m e n t s m u s t b e m a d e over a year in a d v a n c e such d i s a p p o i n t m e n t s m u s t be expected. E a c h m a i n speaker w a s followed b y c o m m e n t s b y a n o t h e r specialist in t h e same field, a n d this led into discussion from t h e audience. B y such a device all subjects were treated with greater d e p t h and diverse opinion, which in t u r n stim ulated excellent discussion from t h e audience. Refreshing was t h e a t t i t u d e of most speakers in stressing t h e limitations of their techniques. T h e y also m a d e it clear- t h a t most problems are solved b y t h e proper combination of m a n y t e c h niques. T h e conventional trace analysis is looked upon as t h e concentration and de termination of a small a m o u n t in a large a m o u n t of sample. However, biochemi cal studies are d e m a n d i n g techniques which will permit t h e analysis of single tissue sections a n d cells weighing 10 ~ 10 to 1 0 - 1 2 g r a m . T h i s problem certainly involves trace quantities, b u t is unique in t h a t when localized areas are analyzed w h a t would be normally regarded as a trace element in this case is n o t so, b e cause in t h e very small localized areas there can be a relatively high concentra tion of t h e constituent. Arne E n g s t r o m , Karolinska I n s t i t u t e ^ outlined recent developments in microradiographic techniques which per-
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5230A. ELECTRIC STIRRER Sparkless
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W. M. WELCH SCIENTIFIC COMPANY DIVISION OF W. M. WELCH MANUFACTURING COMPANY ESTABLISHED 7 8 8 0 1515 Sedgwick Street, Dept. A - 1 Chicago 1 0 , Illinois, U. S. A . Manufacturers of Scientific Instruments and Laboratory Apparatus For further information, circle number 15 A-1 on Readers' Service Card, page 39 A
I
EDOUX'S NEW H Y D R O G E N - D E T E R M I -
Only 20 minutes to determine hydrogen content in most metals^ and alloys , v with the \ new, low-cost...
l NATOR determines hydrogen in T i , Zr, V, W, Ce, Ta, Nb, Co and Ni metals and alloys as well as in many other metallurgical materials. T h e combus tion technique is followed and accu rate determinations are possible in con centrations ranging from 0 . 0 0 3 % to those occurring in t h e metal hydrides. Reduces determination time t o 20 min utes; so simple any technician can operate it; results are more accurate;
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can be used on widely differing metals and alloys; also effective in determin ing C and S; saves operating cost; priced lower than you think. Ledoux's
. . . s o simple any of your technicians can operate it! . . . results are more accurate!
LEDOUX &
1955
new H Y D R O G E N - D E T E R M I N A -
TOR was developed as a result of Ledoux & Co.'s continuous efforts t o bring you newer and better methods and analyti cal instruments. For complete d e t a i l s prices and literature—write to Dept. 13
For further information, circle number 15 A-2
VOLUME
$43.50
COMPANY Teaneck, New Jersey on Readers' Service Card, page 39 A 15 A
