540 INFECTION AND RESISTANCE 



been known that in various pathological conditions of the central 

 nervous system the protein contents of the fluid varied. Thus, the re- 

 actions of Nonne, of Noguchi, etc., were all aimed at revealing an ab- 

 normal globulin content of the spinal fluid. Lange, attempting to ap- 

 ply Zsigmondi's method to the quantitative detection of proteins in the 

 spinal fluid, observed a curious reaction, quite the opposite of what 

 he had set out to find. He observed that spinal fluid, especially of 

 syphilitic cases, in which there was protein material beyond the nor- 

 mal, precipitated rather than protected colloidal gold. He also ob- 

 served that the dilution at which such precipitation took place was 

 more or less constant in syphilitic cases and might therefore be 

 utilized for the diagnosis of such diseases as paresis, locomotor ataxia, 

 etc., etc. The reaction was taken up and carefully studied by a 

 large number of observers, among whom were Zaloziecki, Jaeger and 

 Goldstein, Flesch, Kafka, Lee and Hinton, Miller and Levy, and 

 many others. One of the most practical discussions and clear descrip- 

 tions available for American and English readers is that of Miller, 

 Brush, Hammers, and Felton. The chief difficulty of the test con- 

 sists in the preparation of a proper colloidal gold solution. 



Lange adopted the method used by Zsigmondi with slight modi- 

 fications. He added 10 c.c. of a 1 per cent, solution of gold colloid and 

 10 c.c. of a 2 per cent, solution of potassium carbonate to a liter of 

 carefully and freshly distilled water. The solution was rapidly 

 warmed almost to a boil and just before boiling, while actively stir- 

 ring, 10 c.c. of 1 per cent, formalin solution is added. The solution has 

 remained colorless up to this point but upon this addition should al- 

 most instantaneously become a deep, transparent red. There should 

 be no iridescent or smoky "Schimmer." The utmost care in getting 

 pure distilled water must be exercised and Jena glass must be used 

 throughout. 



Other methods are those of Eicke, who adds dextrose, and many 

 workers, such as Flesch, Kaffge, Eskuchen, and others, have found 

 great difficulty in making up the solution by Lange's technique or by 

 any of the other methods described. Miller and Levy state that 

 with Lange's method good solutions can always be obtained if the 

 water is absolutely pure and the glassware is satisfactorily cleaned ; 

 later, Miller, with the collaborators mentioned above, found that this 

 was not universally true. Also, these writers, as well as Eskuchen, 

 found that occasionally solutions which appeared all right did not 

 react, and special studies followed dealing with the technique of the 

 preparation of the gold sol. Miller and his collaborators find that 

 the reduction method of producing this solution is the best one, and 

 proceed as follows. They use the following reagents : 33 



33 The descriptions are taken direct from the thorough papers of Millr- 

 and Levy. 



