the laboratory of louis pasteur a sturdy air jacket for the freezing-point

THE LABORATORY OF LOUIS PASTEUR PAUL ASH Ball High School, Galveston, Texas

EDITOR'S NOTE.-Mr. Ash was a pupil of Miss Greta Oppe when he undertook the project which he describes here. Other dioramas made by pupils of Miss Oppe weredescribed i n T ~JOURNAL ~ s (13,412-14 (1936)). I had always admired Louis Pasteur and his accomplishments for the furthering of science and prolonging of life. Hence when shown other dioramas in the

medical branch of the University of Texas a t Galveston. It took me approximately four months to develop ideas and blow the chemical glassware. The glassware and apparatus are replicas of those attributed to Pasteur. In the rear of the laboratory are animal cages with a dog in one, calling attention to Pasteur's wonderful work on rabies. ..

A STURDY AIR JACKET FOR THE FREEZING-POINT APPARATUS HAROLD G. CASSIDY' Oberlin College, Oberlin, Ohio

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A DIORAMA OF PASTEUR IN HIS L A ~ O R A T O R V

laboratory a t school, I chose the pasteur theme. Information about old laboratories and the

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life of Pasteur were secured from every source with the help of my father who is a laboratory technician a t the

IN THE determination of freezing points and freezingpoint lowering it is customary to sheath the tube containing the liquid to be frozen in a much larger glass tube which is placed in the freezine mixture and acts as an air-jacket. This jacketing cube is very easily broken. Destruction in elementary classes of a number of these tubes led us to devise a substitute which has served excellently and is practically indestructible. The device is made from large elass tubing 45 to 50 mm. outside diameter with a 2 2.5 mm. wak This is cut in lengths of about 16 cm., one end fire-polished and the other flanged slightly. The bottom of the tube is closed with a No. 9 or No. 10 rubber stopper.

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hesent address: Yale University. N e w Haven, Connecticut.