216 SERIAL SECTION MOUNTING. 



through a Bunsen filter, and adds the glycerin and a little 

 camphor or carbolic acid. 



I find it convenient to beat up the egg with a little water 

 before adding the glycerin and filtering; the salicylate 

 should be dissolved in the water in the first instance. 



According to my experience carbolic acid is perfectly 

 efficient as a preservative, but is not to be recommended 

 because it precipitates a great deal of the albumen. 



A thin layer of the mixture is spread on a cold slide with a 

 fine brush, and the sections laid on it and warmed for some 

 minutes on a water-bath. As the parafiin in the sections 

 melts it carries the albumen away from them, and this is one 

 of the advantages of the method. The sections may be treated 

 with turpentine, alcohol, and aqueous or other stains without 

 any danger of their moving. 



It is not necessary to warm the slide ; the parafiin can be 

 removed in the cold by putting the slide into toluol, xylol, or 

 the like. But the slide should be very thoroughly treated with 

 alcohol after removal of the paraffin, in order to get rid of the 

 glycerin, which will cause cloudiness if not perfectly removed. 



The function of the glycerin is merely to keep the layer of 

 albumen moist. 



This method allows of the staining of sections on the slide 

 with anilin stains, which is seldom practicable with Schalli- 

 baum's method, as the collodion stains with most anilin stains, 

 and does not yield up the colour to alcohol, which the albumen 

 generally does. 



This method can be combined with the water process for 

 flattening out sections ( 280), as described by HENNEGUY 

 (Journ. de VAnat. et de la PhysioL, 1891, p. 398). A drop of 

 water is spread by means of a glass rod on a slide prepared 

 with white-of-egg mixture, the sections are arranged on it, 

 the whole is warmed (not to melting-point of the paraffin) 

 until the sections flatten out, the water is then evaporated off 

 at a temperature of about 40 C., and as soon as it has entirely 

 disappeared the paraffin is melted, and the slide further 

 treated as above described. 



According to my experience the albumen method is abso- 

 lutely safe, and is the one that should in general be preferred 

 for staining on the slide, more especially for staining with 

 anilins by Flemming's method. 



