: the EDITORS l column •
MAXIMUM SAFETY PROVIDED WITH THE WELCH
ELECTRIC STIRRER gfuzukUa*
L.T. Hallett, Editor
INDUCTION TYPE MOTOR
Stabilizing Watt-Type Governor
Vy"AY back in March 1948, we started publishing a section in ANALYTICAL
CHEMISTRY
called
"Crystallographic D a t a . " I n t h e early years the principal source of these items was W a l t e r C. McCrone of Chicago. Later others began t o contribute t o this section. T h e net result has been the publication of d a t a on 230 compounds. M o s t of these are complete with respect t o crystal morphology, crystal optics, x-ray powder d a t a , and unit cell dimensions. AVe believe that this is the largest body of data in the literature in which x-ray and microscopical work for each crystalline phase are correlated. From time to time the question arose as to the desirability 7 of r e producing these items. We discussed t h e m a t t e r with D r . M c Crone. H e suggested that his organization. Walter 0 . McCrone Associates, publish the d a t a in a condensed form. This h a s been done a n d appeared in The Crystal Front (Vol. I, March 1959). This is t h e news letter of W a l t e r C. M c Crone Associates, 501 E a s t 32nd St., Chicago 16, 111. Copies are available on request. In t h e regular issue of A N A L Y T ICAL C H E M I S T R Y , each item t a k e s
about one-half page. I n these new condensed forms, t h e total 230 t a k e up less t h a n 4 pages. This pamphlet will be helpful to those interested in this field, who want a ready reference and pertinent d a t a on t h e crystallography of a wide variety of materials. The value of these d a t a are described by D r . McCrone as follows : The use of crystal properties for the identification and characterization of compounds, organic and inorganic, is becoming more and more common as additional data become available. One of the reason? for this is the high pre-
Speed Adjustable
from 200 to
1400 Revolutions Per Minute - -
An Ideal General Purpose Stirrer
• NON-SPARKING MOTOR • AUTOMATIC SPEED CONTROL • QUIET OPERATION • LONG LIFE 5230. ELECTRIC STIRRER, Sparkless. Complete with 6-foot connecting cord, line switch and plug. For operation on 50 or 60 cycles, 115 volts A.C. Each $54.75
$54.75 No. 5230
5230A. ELECTRIC STIRRER, Sparkless, (or 230 Volts, A.C. Consists of No. 5230 Stirrer equipped with a step-down transformer to permit operation on 230 volts 50 or 60 cycles A.C. Each $64.50
W. M. WELCH SCIENTIFIC COMPANY DIVISION OF WELCH MANUFACTURING COMPANY
— E S T A B L I S H E D 188C 1515 SEDGWICK STREET, DEPT. A - 1 , C H I C A G O 10, ILLINOIS, U.S.A. Manufacturers of Scientific Instruments and Laboratory Apparatus
new
HEVI-DUTY
C I R c i O ) " T H E R I V I OVEN Temperatures to 250° C. (480° F.) Improved T e m p e r a t u r e Uniformity. W i t h Hevi-Duty's "circleof h e a t " design, there are no cold corners. Fast Heat-Up. T o 200° C. in less than one hour. Low-Cost Operation on either 115 or 230 volts. Selector switch permits high or low input to enclosed heating elements. Durable D o u b l e - W a l l Construct i o n . S t e e l o u t e r s h e l l is p r i m e Model
HK HL
Chambe Price
$169. $265.
Size
Diameter
Depth
15 20
13 18
coated on both sides to prevent corrosion. Accurate T e m p e r a t u r e Control by sensitive bulb-type thermostat permits little lag or overshoot. For complete information, write for Bulletin 458. Overall Dimensions
Walts
Volts
600 1000
115/230 115
Width
Depth
Height
Shipping Weight
20 25
18 23
23 28
80 100
Salute to
Will's
HEVI-DUTY
first 40 years
Milwaukee 1, Wisconsin
Circle No. 133 on Readers' Service Card
VOL. 3 1 , NO. 7, JULY 1959 ·
59 A
