Dr. H. E. RADASCH Daniel Baugh Institute of Anatomy WHITE MICE FOR SALE Laboratory Stock, $30 a hundred, F. O. B. Garrison, N. Y. The Laboratory Animal Supply Co. GAS-GAS The portable outfit illustrated herewith produces an abundance of ultra-violet radiation with which a number of very interesting fluorescent effects may be produced. For example, the following curious properties may be readily demonstrated: If the light from the iron spark is directed on a lump of willemite, the latter will glow with a beautiful green fluorescence. If a thin plate of glass or clear mica is now placed between the iron spark and the willemite, the green fluorescence of the latter will instantly vanish, and it will appear in its natural color as seen by daylight or any ordinary artificial light. If now a plate of clear quartz or selenite is substituted for the glass or mica, the willemite will continue to glow with its characteristic green fluorescence. It is thus made evident that the glass and mica are opaque to the ultra-violet rays which produce fluorescence, while the quartz and selenite are transparent to them. This experiment may be tried with any fluorescent substance other than willemite with similar results. The outfit operates on 110 volts (60 cycles) alternating current-and requires about 300 watts. If interested, please write for Descriptive Bulletin X 223 JAMES G. BIDDLE 1211-13 ARCH STREET AMINOIDS for Culture Media SUPPLIES AMINO ACIDS in definite standardized amounts OFFERS nutritional nitrogen in immediately available form for bacterial utilization PREPARED in two forms 1. Aminoids (Biuret-free). (Beef or Casein.) In this second preparation 50% of the total Nitrogen is present in Descriptive letter prices. The Arlington Chemical Company YONKERS, N. Y. PALO Our new supplementary catalogue is ready for distribution. It comprises glass apparatus of precision made according to the Requirements of the U. S. Bureau of Standards NORMAL BECKMANN CALORIMETER THERMOMETERS The catalogue describes some entirely new apparatus and includes valuable data and information which makes it a most useful book. Write for your Copy PALO COMPANY LABORATORY APPARATUS AND CHEMICALS 90-94 Maiden Lane NEW YORK CITY FRY LONG BEFORE THE GREAT WAR THE NAME FRY STOOD LABORATORY YOUR DEALER WILL SUPPLY YOU BOOKLET AND PRICE LIST MAILED UPON REQUEST. H. C. FRY GLASS CO. ROCHESTER PENNSYLVANIA Seamless WE Fat-free WHATMAT Extraction Thimble Now in a large variety of Sole Representatives in the U. S. A. and Canada H. REEVE ANGEL & CO., Inc. 7 to 11 Spruce Street Order from your Dealer BARNSTEAD WATER STILLS THAT these stills produce double-distilled water of unequalled purity, free from ammonia and other organic impurities, has been the experience of thousands of users, including A remarkably low cost per gallon is the result of preheating the incoming raw water by using it Barnstead Stills are automatic in operation, requiring practically no attention after being started. They are quite compact yet for thorough cleaning the boiler is completely accessible by simply turning a few thumb screws. Branch Office and Showroom: 2011 Jenkins Arcade, PITTSBURGH, PA. SARGENT'S ELECTRIC DRYING OVEN With Automatic Temperature Control (Patented Jan. 6, 1914) This is the pioneer of moderate-priced ovens in this class, and the hundreds now in satisfactory operation prove its success. This end has been achieved by ruggedness of construction, elegance of design and due observance of the scientific principles which are demanded in drying ovens. Its extreme simplicity precludes the imitation of its patented features and enables it to maintain its position as the best and cheapest apparatus on the market for its purpose. Extended Descriptive Circular on Application Price complete, with six foot cord, plug for connection to lamp socket and thermometer $27.50 net. E. H. SARGENT & CO. Importers, Makers and Dealers in Chemicals and Chemical Apparatus of High Grade Only 125-127 W. Lake St. Chicago, Ill. |