Cork 299 borer, press

An apparatus for the filtration of small to moderate quantities of crystals incorporates the so-called Willstatter filtration nail. The latter consists of a thin glass rod flattened at one end. It is readily constructed by heating the end of a short glass rod in the blowpipe flame and pressing vertically upon an asbestos board. The nail is fitted into small glass funnel it is covered by a circle of a filter paper cut with the aid of a cork borer of appropriate size. A filtration nail r r and funnel, capable of handling up to 1 g. of solid is depicted... 

Soy flour is brought to approximately 40% (w/w) moisture content with distilled water. The dough obtained is kneaded, rolled flat, and then pressed between glass plates to give it the shape of a film. It is then left overnight in a refrigerator at 4 to 5°C. The dough that becomes easily workable is then cut into small disks with a cork borer for diffusion experiments. 

Cork borers Cork press Crock for waste Funnel support... 

Lehrbuch der pharmaceutischen Techniky 1847 2 ed., 1853 (Beindorf s apparatus 74 Liebig s condenser 195 sp. gr. balance 348 cork press 431, nest of cork borers 374 etc.) 3 ed., 1866. The sp. gr. balance was an ordinary balance (9iin. beam) with a glass tube sinker, weighted with mercury, suspended by a fine platinum wire. The Westphal balance was described by Oertling, Z. anal. Ghent, y 1868, vii, 294. 

The following procedure has been described in the literature [42] The electroactive material is thoroughly mixed with a sufficient amount (50 weight %) of silicone rubber cement (for example Clear Seal , a rubber vulcanized at room temperature, by General Electric, U.S.A.) and pressed to an approximately 0.5 mm thick membrane between two flat plates. After hardening in air, a piece is cut out with a cork-borer and fixed into the end of a suitable borosilicate glass tube with some additional silicone rubber cement. This step requires much care, since any contact between the inner solution and the sample solution will destroy the ion-selectivity. 

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