NEW CHEMICALS Single Crystal Chips Over 250 different kinds of single crystal chips are available to supplement the normal commercial single crystal production. These single crystal chips are a source of high purity material with controlled additives and are the most economical method of determining parameters before spending large funds on big crystals. Chip sizes are 1 to 4 mm. in cross section up to 5 to 10 mm. in length depending on the technical difficulties of crystal growth. Prices range from $15 to $50 per chip. Semi-Elements, Inc., Saxonburg Blvd., Saxonburg, Pa. 501 Labeled Compounds Labeled compounds available commercially for the first time include seven carbon-14 labeled carbohydrate phosphates, with specific activities which vary from 3 to 15 mc. per mM. Also newly available are eight phosphorus-32 labeled nucleotides and six phosphorus-32 labeled carbohydrates. These compounds are shipped as sodium salt in neutral aqueous solution and have specific activities greater than 200 mc. per mM. International Chemical and Nuclear Corp., 13332 E. Amar Rd., City of Industry, Calif. 502 High Purity Helium-3 High purity helium-3 suitable for use as a vapor pressure standard for measuring temperatures between 0.3° and 3.2° Kelvin is available. This is the culmination of a cooperative effort between the Los Alamos Scientific Laboratory, the National Bureau of Standards, and Mound laboratory to establish the vapor pressure of helium-3 as the international temperature scale between 0.3° and 3.2° K. The helium-3 for use as a vapor pressure standard will be distributed at two atmospheres pressure in 500-ml. containers. The Bureau will certify that the individual samples withdrawn contain greater than 99.98% helium-3 with respect to total helium. Helium-3 is useful as a cryogenic bath for studying other substances at low temperatures, as a neutron detector, and in activation analysis. Further information is available from Gaseous Isotope Sales, Monsanto Research Corp., Mound Laboratory, Miamisburg, Ohio. 503
PINPOINT NEW
FISHER
ENDPOINTS
PRECISELY
WITH
Precision
electronics,
TITRIMETER
wide choice of electrodes permit exceptionally close determination of titration endpoints. Range: 0 to ± 1 4 0 0 mv, 0 to 14 pH. Resolution:
±2 mv,
± 0 . 0 2 pH. Accuracy:
± 0 . 5 % . New Titrimeter,
Fisher's potentiometric titrator (patent pending), comes in two designs: Model 35 for manual titrations; time-saving Model 36 for automatic and manual titration. Optional accessory kits for microand Karl Fischer titrations. Full details from your nearest Fisher branch, or write Fisher Scientific Company, 100 Fisher Building, Pittsburgh 19, Pa., for information Bulletin FS-247.
FISHER SCIENTIFIC World's Largest Manufacturer-Distributor of Laboratory Appliances & Reagent Chemicals Boston • Chicago • Fort Worth • Houston • New York • Odessa, Tex. • Philadelphia Pittsburgh • St. Louis • Union, N. J. • Washington • Edmonton • Montreal • Toronto Circle No. 135 on Readers' Service Card
