DE-ALCOHOL1SATION AND CLEARING AGENTS. 85 



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

 celloidin sections. 



119. GAGE'S Mixture (Proc. Amer. Soc. Micr., 1890, p. 120; Journ. 

 Boy. Mlc. Soc., 1891, p. 418). Carbolic acid crystals melted, 40c.c. ; oil of 

 turpentine, 60 c.c. 



120. Creasote. Much the same properties as carbolic acid. 

 Beecli-wuod creasote is the sort that should be preferred for 

 many purposes, amongst others, for clearing celloidin 

 .sections, for which it is a very good medium. 



121. Anilin Oil. This is a rather important reagent on account of its 

 ability to clear excessively watery objects. Common anilin oil will readily 

 clear sections from 70 per cent, alcohol, and with certain precautions (for 

 which see the paper of SUCHAXXEK quoted below) objects may be cleared 

 from watery media without the intervention of alcohol at all. This pro- 

 perty renders anilin valuable in certain cases as a penetrating medium for 

 preparing for paraffin imbedding. For ordinary work the usual commercial 

 anilin will suffice; and it is immaterial whether it be colourless or have 

 become brown through oxidation. For difficult work it is well to use a 

 perfectly anhydrous oil. For directions for preparing this see SUCHANXEK, 

 Zeit.f. iviss. Mik., vii, 2, 1890, p. 156, or the third edition of this work. 



Anilin is chiefly used for clearing celloidin sections, and is sometimes 

 found very valuable fur this purpose. 



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

 recommeiidable as clearing agents in which it is desired to 

 examine specimens,, but very useful for preparing paraffin 

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

 benzol is the most volatile, then toluol, and xylol is the least 

 volatile, in the proportion of 4 : 5 : 9 (SQUIRE, J\Ietltu<~l* and 

 Formulae, p. 20). Chloroform is injurious to some delicate 

 stains, but is in other respects an excellent de-alcoholisatioii 

 agent, as it will take up a good deal of water, if any be left 

 in the preparations. 1 consider it too volatile for use before 

 balsam. Xylol is the best of these in that respect ; but it 

 has the defect of mixing very slowly with alcohol. I now 

 generally bring my sections from alcohol first into chloroform, 

 to remove the alcohol ; then into xylol, and thence into the 

 balsam. 



123. Amyl Alcohol. JAXSSEXS (La Cellule, xiv. 1, 1898, p. 209) 

 treats cover-glass preparations, taken from 95 per cent, alcohol, with amyl 



