A CONVENIENT APPARATUS FOR HOLDING FUNNELS WHILE FILTERING INTO BEAKERS ELI JAH SWIFT, JR. Harvard University, Cambridge, Massachusetts
THE usual device employed in the elementary &emistry laboratory to hold a funnel while filtering into a heaker is either a wooden hoard with holes drilled through it, or else an iron ring clamped to a ringstand. Both of these devices are somewhat clumsy, slow to adjust properly, and very apt to accumulate dii. A device which has none of these disadvantages and is easy and cheap to make has been used by the author for several years. It consists of a small glass or metal piece designed to fit over the rim of a heaker and hold a funnel securely there. Figure 1 shows the position of the apparatus in use. The apparatus may be made of either metal or glass. The metallic form is not so fragile, but may be liable to corrosion unless varnished. Figure 2 shows the approximate dimensions of the pattern for both types. The ends B-B are bent away from the plane of the paper so that they fit snugly around the curve of a 400-cc. beaker. The ends are bent up so that they come up and rest firmly under the rim. There is a bend a t C which fits around and over the rim, in such a way that the hole A is slightly below the level of the rim. I n practice, the apparatus is slipped over the rim of
the beaker, and the funnel inserted. The tip of the funnel will rest against the edge of the beaker about halfway down. It will be found impossible to tilt the funnel more than a few degrees in any direction. The set-up may he lifted with one hand and moved to the side without danger of losing drops from the tip of the funnel. It will be found that with the adiustment made -~~ for a 400-cc. heaker, the device will work equally well
on all sizes from 150 cc. to 600 cc. Moreover, on the larger sizes several funnels can he set around the edge of a heaker to speed up the filtration.
