90 JOURNAL OF THE [J^^Y, 



to alcohol of 80 per cent, both fihii and support will be moist- 

 ened by it. This fact will prove that the turpentine has been 

 successfully removed. In this alcohol of 80 per cent, the sec- 

 tions may be preserved for any length of time. 



To proceed, a bath of 10 per cent, alcohol follows until the 

 film is thoroughly soaked. After this is done sections and film 

 moisten, when in contact with aqueous solutions, and the sections 

 can be stained by the proper staining fluids. When it is possible, 

 however, it is advisable to add a small quantity of alcohol, as a 

 small percentage of this in staining fluids greatly increases their 

 penetrating power. 



In case two different liquids — one as a mordant — are to be 

 used to produce the staining, it is necessary to employ the mor- 

 dant on the whole object before the embedding process, because 

 in this way the collodion and paper are not stained, but only 

 the sections. Over staining is reduced in the usual way. 



d. For the purpose of transferring the film and support to 

 turpentine again, it is necessary only to dry both superficially 

 between filtering papers and then to immerse them in creosote, 

 oil of origanum or liquified carbolic acid (i to 3 xylol, accord- 

 ing to Weigert) ; or, better, to bring them first to alcohol of 80 

 per cent.', before employing these liquids. Then lay this sup- 

 port — film underneath — on filtering paper soaked with creosote, 

 and, after film and sections are made transparent, transfer to 

 turpentine. 



e. Finally, the borders or lines of perforations made by the 

 dented wheel are cut off, film and support — film underneath — 

 are laid on thin paper, on which is a coat of rosin and turpen- 

 tine. Air-bubbles between paper and film must be avoided, 

 and the paper, which has so far formed the support is pulled off. 

 A coat of rosin in turpentine is applied to the now exposed lower 

 side of the film, and another thin paper laid flat on this. Tur- 

 pentine penetrating the thin paper must be blotted off. 



Instead of enclosing thus in rosin and a provisory support, 

 the film with the sections may be mounted on slides in the usual 

 way. Numbers or notes, to be enclosed at the same time with 

 the sections in the collodion-film, should be written on thin 

 paper with a soft lead-pencil, or with india-ink. 



