DE-ALCOHOLISATION AND CLEARING AflKNTS. 7^ 



mended by MAYER, Zeit. wi. Mikr., xxvi, 1910, p. 523. 

 Clears from alcohol of 90 per cent., or even 80 per cent. 



132. Carbolic Acid. Best used in concentrated solution in 

 alcohol. Clears instantaneously, even very watery prepara- 

 tions. This is a very good medium, but it is better avoided 

 for preparations of soft parts which it is intended to mount 

 in balsam, as they generally shrink by exosmosis when placed 

 in the latter medium. It is, however, a good medium for 

 celloidin sections. 



GAGE'S Mixture (Proc. Amer. Soc. Micr., 1890, p. 120). Carbolic 

 acid crystals melted, 40 c.c. ; oil of turpentine, 60 c.c. 



133. Creosote. Much the same properties as carbolic acid. 

 Beech-wood creosote is the sort that should be preferred for 

 many purposes, amongst others, for clearing celloidin sec- 

 tions, for which it is a very good medium. 



134. Anilin Oil. Common anilin oil will readily clear 

 sections from 70 per cent, alcoliol, and with certain pre- 

 cautions (for which see the paper of SUCHANNEK quoted 

 below) objects may be cleared from watery media without 

 the intervention of alcohol at all. This renders it valuable 

 in certain cases as a medium for preparing for paraffin 

 imbedding. For ordinary work the usual commercial anilin 

 will suffice; and it is immaterial whether it be colourless <>r 

 have become brown through oxidation. For difficult work 

 it is well to use a perfectly anhydrous oil. For directions 

 for preparing this see SUCHANNEK, Zeit. wixs. J\Jik., vii, 1890, 

 p. 156, or the third edition of this work. 



Anilin is chiefly used for clearing celloidin sections. It 

 ought however to be soaked out before mounting by some- 

 thing else (chloroform or xylol for instance for some hours), 

 as if not removed it will brown both the tissues and Un- 

 mounting medium. 



135. Xylol, Benzol, Toluol, Chloroform. Too volatile to be 

 recommendable as clearing agents in which it is desired t<> 

 examine specimens, but very useful for preparing pnrnllin 

 sections for balsam. Of the three first-mentioned liquids, 

 benzol is the most volatile, then toluol, and xylol is the le.-ist 

 volatile, in the proportion of 4 : 5: 9 (Snui,% Mrtlnnlx n<l 



