Electronic osmometer with rigid membrane of copper ferrocyanide.

A Rigid Membrane for Measurement of Colloidal Osmotic Pressure with the Hepp Osmometer **

The Extracellular Space in the Toad Retina as Defined by the Distribution of Ferrocyanide

Measurements of the uptake of compounds that ordinarily do not penetrate into cells have been a source of data on the size of the extracellular space in nervous tissue. The distribution of one such compound, ferrocyanide, has been studied in the toad retina by means of the light and electron microscopes. At the level of the light microscope, ferrocyanide, detected as Prussian blue, appears to p...

Titrations with ferrocyanide of japanese-lacquer-tree (Rhus vernicifera) laccase and of the type 2 copper-depleted enzyme. Interrelation of the copper sites.

1. Redox titrations are reported of the metal centres in Japanese-lacquer-tree (Rhus vernicifera) laccase with ferrocyanide. 2. The redox potential of Type 1 Cu was found to increase with ferrocyanide concentration up to a limiting value similar to that for the Type 1 Cu in Type 2 Cu-depleted enzyme (which is independent of ferrocyanide concentration). 3. The redox potential of the two-electron...

Pfeffer Cell Apparatus

The Pfeffer Zelle (Pfeffer Cell Apparatus), invented by Wilhelm Pfeffer [6] in 1877, measured the minimum pressure needed to prevent a pure solvent from passing into a solution across a semi-permeable membrane, called osmotic pressure. The apparatus provided Pfeffer with a way to quantitatively measure osmotic pressure. Pfeffer devised the apparatus in the 1870s at the University of Basel [7] i...

Studies on crystal semi-permeable membrane. I. On the formation of the semi-permeable membrane of calcium carbonate.

present for the formation mechanism. A famous •gPfeffer's semi-permeable membrane•h made of potassium ferrocyanide and copper sulfate in unglazed pottery cylinder by W. Pfeffer in 1877 is quite different from an artificial semi-permeable membrane at present, which is organized only by handling of extending high molecular substances, that is, collodium, cellophane, and various synthetic resins. ...