CUTTING AND MOUNTING SECTIONS. 297 



a water-bath, in order to evaporate the clove oil. The 

 sections may next be freed from the embedding mass and 

 colored according to desire. Gage recommends that 

 the collodion and clove oil be applied separately.* 

 "The paraffine is now removed and the sections are 

 stained, generally with borax-carmine, which two operations 

 are performed as follows: A series of glass tubes large enough 

 to hold a slide is filled with the following reagents, and 

 arranged in the following order: Turpentine (or naphtha); 

 absolute alcohol; 90 per cent alcohol; 70 per cent alcohol; 

 alcoholic borax-carmine; 70 per cent alcohol acidulated with 

 HC1; 90 per cent alcohol; absolute alcohol. The slide, 

 having been warmed to the melting-point of the paraffine, 

 is plunged into the turpentine, which removes the paraffine; 

 then passed through the tubes with the successive alco- 

 hols into the stain, from which it is brought into the suc- 

 cessive alcohols of the ascending series, which wash out the 

 stain and dehydrate the sections. Nothing more now re- 

 mains to be done but to treat the sections with a drop of ben- 

 zol or turpentine, and to add Canada balsam and a covering- 

 glass." 



When the objects are small and sufficiently permeable, 

 the sections can be stained on the slide. ' ' In this case the 

 object after having been fixed and washed out is taken 

 while still on its way through the lower alcohols (it should 

 not be allowed to proceed to the higher grades of alcohol 

 before staining) and passed through a bath of alcoholic 

 borax-carmine (or other alcoholic stain) of sufficient dura- 

 tion, then dehydrated with successive alcohols, passed 

 through chloroform into paraffiue, and cut as above 

 described. " \ 



* See Whitman's Methods of Research in Microscopical Anatomy 

 and Embryology, pp. 121, 122. 



f If the objects have already been soaked in clove-oil, or other 

 essential oil, for the purpose of clearing, they may either be embedded 

 direct from the clove-oil, or this may be removed by means of 

 chloroform, which is the better practice (Lee). 



