THE PREPARATION AND STANDARDIZATION OF COLLODION MEMBRANES

Abstract

The use of collodion membranes in the study of diffusion phenomena was begun by Fick (1855); the closed collodion sac was devised 5 years later by Schumacher (1860).Metchnikoff, Roux, and Taurelli-Salimbeni ( 1896), in their researches on the vibrio of Asiatic cholera introduced these sacs into biological science.Because of their ease of preparation, availability, thinness, and ready permeability to ordinary crystalloids, they have largely replaced the older parchment paper membranes in the study of dialysis and diffusion.For a complete bibliography and literature review of this development of their' use, the reader is referred to t,he paper of Bigelow and Gemberling (1907).Mention should be made, however, of the work of Gorsline (1903), who showed that crystalloids were not the only substances that could diffuse through a collodion membrane, for at 35"C., peptone, albumose, albumin, starch, dextrin, and certain enzymes all dialyzed through in less than 24 hours in recognizable quantities.The first successful attempt to produce a graded series of membranes of increasing permeability was made by Bechhold (1907Bechhold ( , 1908)).By impregnating filter papers with varying percentage strengths of gelatin or glacial acetic acid collodion, he produced membranes whose permeability varied inversely with the concentration of the impregnating solution.These membranes were used as filters.With the use of pressure, often many atmospheres, substances like hemoglobin, albumin, and various inorganic colloids were filtered through.A mechanical stirring device was employed to prevent the precipitation of the colloid on the surface of the membrane; such precipitated colloid 203