A Locknut for a Weight Buret hIARTIN KILPATRICK, University of Pennsylvania, Philadelphia, Penna.
I
S THE use of weight burets in this laboratory the problem of keeping the ground cup in place during transfer to and from the balance has been solved as described below. The buret itself is similar t o t h a t outlined by Shedlovsky and Brown ( I ) , being without a stopcock a t the bottom; the additional feature is the “locknut” device sho-m in the diagram, b y which the cup is held in place.
C
A is a vertical section through the slotted bell-shaped apron fused on the buret above the ground-glass joint for the cup. Below it is a section of the cup. The sections were made in the following manner: The left half of each of these two sections represents the section cut by a vertical plane whose direction is represented on drawing B by its trace, which is the radius to E. The right half represents the section cut by a plane whose trace is the radius to F . This was done in order to show clearly the position of the slots in the foldedunder edge of the bell-shaped apron. The slots are actually on opposite ends of a diameter, as shown in horizontal sections B and C, taken through X Y with the cup in place. Horizontal section B shows the buret as the wing 1, is slipped into the slot a t l’, and C shows the same section after a rotation of the cup through 90”.
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At all positions except t h a t illustrated in B , the cup is firmly locked in place, and cannot fall off. The same design can be adapted t o burets with stopcock a t the bott,om by constructing the bell just below the stopcock.
Literature Cited (1) Shedlovsky and Brown, J . Am. Chem. SOC.,56, 1066 (1933).
Laboratory Juice Extractor GEORGE W. IRVISG, JK., AND THEODORE W. LORING Department of Biochemistry, Cornell University Medical College, New York, N. Y.
IN
BIOCHEMICAL investigations it is frequently necessary to effect a rapid and fairly complete separation of fluids from animal or plant tissues. Recently, the authors were confronted with the necessity of making such a separation in connection with work upon the hormones of the posterior lobe of the pituitary gland. I n this instance they wished t o make a purely mechanical separation of the fluid contained in fresh glands from the gland tissue. F I G ~ R1.E CROSSS E C T I O N ADLI A GRAM OF JCICE EXTRACTOR A , piston; H , cylind e r ; K ,base; F , removable, perforate: steel plate; B a n d B , channels in cylinder a n d base, sloped tow a r d t h e vertica) and D , channel, C; felt filter disks; E , material t o be pressed; G , spout through which e x p r e s s e d f l u i d is collected
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A fairly satisfactory separation was accomplished by means of the 2.25-inch test cylinder of the familiar Carver laboratory press. The gland material w s thoroughly macerated with sand and the fluid was expressed by subjecting the ground mass to high pressure in the test cylinder. The press juice, together with the viash fluids, was found to contain the active material desired in almost quantitative yield, while the press cake of sand and residue contained only traces of activity. Extensive use of the Carver equipment for this purpose revealed several disadvantages. In using the Carver test cylinder, the material to be pressed was placed in the cylinder between two felt filter disks and the fluid v a s expressed by applying pressure to the piston. Since the bottom of the cylinder is not perforated,
