DRUMMOND
"MICROCAPS"® BURRELL
"For
Scientists
Everywhere"
LABORATORY FURNACE variable temperature range to 2 8 0 0 ° f
(Disposable micro-pipettes) These pipettes consist o f short lengths of p r e cision m a d e c a p i l l a r y glass t u b i n g , c a l i b r a t e d t o contain a definite volume f r o m end to end. They a r e accurate to within 1 % or less and are so low in cost that you can a f f o r d t o use them once and discard them. W h i l e they are of g r e a t value in general micro-chemical applications, they are especially useful in the handling o f dangerous m a t e r i a l . No particular skill is needed in order to obtain accurate resulls. " M i c r o c a p s " may be used in a number o f different w a y s . The most p o p u l a r technique is as follows: The pipette is inserted through Ihe rubber cap on the end of the rubber bulb as sembly f a r enough to become visible through Ihe glass tube. A hole in the rubber bulb permits f r e e cir culation of air, so that the pipette may be filled by c a p i l lary altraction. W h e n filled from end t o end, the p i p e t t e contains the stated volume. To discharge: hold finger over the hole in the bulb and squeeze. To rinse, r e p e a t the operation with the diluent.
A versatile laboratory fur nace for reliable operation from the lowest to the high est temperatures. From 600° F. to 2000° F., use for ashing, drawing, ig niting and tempering, above 2000° F., for sintering, melt ing, clinkering, fusing and high-speed hardening.
Another convenient method, when using pipettes o f 20 lambdas capacity or l a r g e r , is to discard the bulb assembly a n d , holding Ihe p i p e t t e with the fingers (or a pair of tweez ers), f i l l it by c a p i l l a r y attrac tion. Drop the p i p e t t e into a test tube containing the diluent and stopper. A short vigorous shaking w i l l wash the contents of the pipette into the diluent. The bore in the tubing f r o m which " M i c r o c a p s " a r e m a d e is so constant that the volume o f a p a r t i a l l y filled tube may be determined by simply calcu lating the volume per linear mm by means of an o r d i n a r y metric scale. Example: Suppose a 5 0 l a m b d a p i p e t t e measures 1 0 0 mm in length; this means that each mm in length contains 0.5 lambdas. Therefore, should you find hat the p a r t i a l volume measures 5 6 m m in length, you would know that this volume equals 2 3 lambdas.
BURRELL BOX-MUFFLE TYPE FURNACE, Model 30 Heating chamber 7" wide χ 8^4" deep χ 4" high. For use with 230 volt, 50-60 cycle, single phase power supply, or with automatic controller for 115 volt, 50-60 cycle, single phase. Burrell Cat. N o . 3 7 - 4 4 2
$1600.
F.O.B. P i t t s b u r g h , P a .
Ask for Bulletin No. 315
BURRELL
CORPORATION
Scientific Instruments and Laboratory Supplies 2 2 2 3 FIFTH AVENUE, PITTSBURGH 19, PA.
Microcaps a r e stocked in the f o l l o w i n g sizes: 1 , 2, 3 , 4 , 5 , 1 0 , 1 5, 2 0 , 2 5 , 3 0 , 4 0 , 5 0 , 75 a n d 1 0 0 l a m b d a c a p a c i t y . Special sizes are a v a i l a b l e on short notice. PRICES:
Sizes f r o m 1 to 5 0 l a m b d a inclusive, $ 4 . 5 0 per v i a l o f 1 0 0 , including bulb assembly. Sizes over 5 0 to 1 0 0 l a m b d a s , $ 5 . 5 0 per v i a l of 1 0 0 . Quantity discount: less 1 0 % in lots o f 1 2 vials or more. Send for samples
M a d e i n U.S.A. b y
DRUMMOND SCIENTIFIC CO. 5 0 0 P a r k w a y South BROOMALL, PA. Circle No. 123 on Readers' Service Card 108 A
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ANALYTICAL CHEMISTRY
Circle No. 159 on Readers' Service Card Circle No. 119 on Readers' Service Card
