iqiq] current literature 373 



raised bogs, this report stands as one of the most notable of recent years. — 

 Geo. D. Fuller. 



A new fixative for paraffin sections. — Dr. Koloman Szombathy^ describes 

 a new method of fixing paraftm sections to the sHde. The fixative is claimed to 

 have the advantage of not being dissolved by alkaline stains, and furthermore 

 in not being stained by hematins and aniline stains such as eosin fuchsin, orange 

 G., etc. The formula given by him is as follows: gelatin i gm., distilled water 

 loo cc, salicylate of soda (a 2 per cent solution) i cc, pure glycerine 15 cc. 



Dissolve the gelatin in water at 30°, add the salicylate of soda, shake well, 

 cool, and filter. To this add 15 gm. of pure glycerine. The solution obtained 

 should be perfectly clear. A small amount of the fixative together with a drop 

 or two of a 2 per cent formalin solution is placed on the slide, smeared evenly 

 over the surface, and rubbed in well. Care should be observed that the formahn 

 is mixed with the fixative. The sections or parafiin ribbons are then placed 

 on the fixative and permitted to dry in the thermostat or any other warm place 

 which is protected from dust. The formalin "tans" the gelatin and makes it 

 insoluble. A modification of the method consists in exposing the slides, which 

 have been mounted without the use of formalin solution, to vapors of con- 

 centrated formahn in a thermostat. The effect of the formahn is identical. 

 A third method consists in preparing a solution of equal parts of i per cent 

 gelatin in water and 2 per cent formalin. The fixative is then used as recom- 

 mended for albumen fixative. 



The writer has tested the fixative recommended by Szombathy and finds 

 it to be an excellent one. Material known to be difficult to retain on the shde 

 was tried out. Sections of grass leaves and moss archegonia adhered to the 

 slide even when the latter were left in running water for several days or exposed 

 to a strong solution of hydrogen peroxide. Alkahne stains do not dissolve the 

 gelatin nor do the stains tested stain the background to an appreciable extent. 



Of the 3 methods originally recommended, the following modification gives 

 the most satisfactory results. Make up the fixative according to the first 

 formula, put a drop on the slide, and smear it evenly over the surface. Float 

 the paraffin ribbon on the shde on a 2 per cent formahn solution. Warm the 

 sUde gently on the usual copper plate and, after the ribbon has straightened 

 and become smooth, drain off the surplus water and let the preparation dry. 

 When one is deahng with material which does not stick to the shde easily, it 

 will be found of advantage to put a small dish of formahn in the thermostat 

 where the preparations are drying, since the formalin vapors help in rendering 

 the gelatin insoluble. 



This new fixative is very easily prepared, keeps well, and does hold the 

 sections to the slide. It should come into general use especially for material 

 which does not adhere to the slide under ordinary conditions and when stains 



7 Szombathy, Koloman, Neue Methode zum Aufkleben von Parafi&nschmitten . 

 Zeitschr. Wiss. Mikr. 34:334-336. 1918. 



