Influence of sodium chloride crystallization by cerebrospinal fluid

Abstract

F OLLOWING the evaporation of a salt solution there results crystal formation which is specific for each salt and is the so-called crystal habit of the salt. Various workers have shown that the crystal formation of a salt may be easily affected by many factors. The minutest impurity in the salt solution will influence the crystal habit. Semenchenko and Shikhobalaval showed that the surface tension of the salt solution was the most important factor influencing the crystallization. Changes in the surface tension are reflected by changes in the crystal habit. These workers showed that the crystallization of sodium nitrate by evaporation is hardly influenced by substances which cannot change the surface tension of this salt. By the addition of surfaceactive substances a typical change of the crystal configuration is possible. Among the most important surface-active substances are albumin and globulin. These physicochemical facts were first used by Pfeiffer,’ who noted that the addition of minute quantities of blood influenced the crystallization of a copper chloride solution. He further observed that blood from a tuberculous or cancerous patient gave a different type of crystal formation than did normal blood. He felt that by this method a serologic diagnosis of certain diseases was possible. Tomesco and his co-workers3 used the same principle for the study of the cerebrospinal fluid. They added minute quantities of cerebrospinal fluid to physiologic saline solution. They then studied the results of the crystallization by evaporation of this mixture at a temperature of 75” C. The evaporation of 3 drops of physiologic saline solution results macroscopically in the formation of an outer ring surrounding an empty space. Microscopically, the sodium chloride crystals have a cubical shape. The addition of normal cerebrospinal fluid changes this picture. Tomesco and his associates found that the normal cerebrospinal fluid is able to change the crystallization in a dilution of I:20 up to 1:60 or 1930. Macroscopically, the evaporation of 3 drops on a slide shows a crystalline circumference enclosing a translucent layer. With higher dilutions this translucent layer disappears, and one sees only empty spaces, i.e., the same picture as seen without the addition of cerebrospinal fluid. Microscopically, the translucent area consists of rosettes, concentric circles, parallel lines, and needles.