SERIAL SECTION MOUNTING. 151 



per cent, alcohol, or may be brought into a staining fluid. 

 The watery fluid causes the double sheet of collodion to 

 become detached from the glass, holding the sections fast 

 between its folds. It is then easy to stain, wash, dehydrate, 

 and mount in the usual way, merely taking care not to use 

 alcohol of more than 90 to 96 per cent, for dehydration. 

 Weigert recommends for clearing the mixture of xylol and 

 carbolic acid ( 361). 



The series should be cut into the desired lengths for 

 mounting- whilst in the alcohol. It is perhaps safer to lay 

 them out for cutting on a strip of closet paper saturated with 

 alcohol. 



A good method for larye and illicit sections that do not 

 require flattening, not for series of small thin ones. 



It is suggested by STRASSER that gurntned paper might be an improve- 

 ment on the glass plates used in this process especially for very large 

 sections. 



The modification of.. Weigert 's method proposed by WINTERSTEIXER (Zeit. 

 f. iviss. Mik., x, 3, 1893, p. 316) consists in suppressing the alignment of 

 the sections on the strip of paper, a,nd slipping them direct from the knife 

 on to the prepared glass. 



196. OBREQIA'S Method for Paraffin or Celloidin. Sections. 

 This method was originally described in the Neurologisclies 

 Ceniralli., ix, 1890, p. 295, and is given in the third edition 

 of WOODHKAD'S Practical Pathology. It is described with 

 modifications by GULLAND, Journ. of Patli., February, 1893. 

 Slides, or glass plates of any size, are coated with a solution 

 made of 



Syrupy solution of powdered candy- 

 sugar made with boiling distilled 

 water . . . . . 30 c.c. 

 95 per cent, alcohol . . . 20 ,, 

 Transparent syrupy solution of pure 

 dextrin made by boiling with dis- 

 tilled water 10 



They are dried slowly for two or three days until the 

 surface is just sticky to the moist finger. Paraffin sections 

 are arranged and heated for a few minutes to a temperature 

 slightly above the melting-point of the paraffin. The paraffin 

 is removed by some solvent, such as xylol or naphtha, and 



