178 THE AMERICAN MONTHLY [June, 



corrosive sublimate and the hardening completed in alcohol ; or 

 they may be placed at once in a large quantity of Mailer's fluid 

 and after two weeks transferred to alcohol. After the hardening 

 is complete keep the specimens in 80 per cent alcohol. The size 

 of the specimen should be small and the quantity of the fixing 

 fluid large; this rule must be faithfully followed if good results 

 are to be obtained. 

 1._When Paraffin is Used. 2.— When Celloidin is Used. 



80 per cent alcohol, (a). 80 per cent alcohol 



Stain lb). AbsoluJ^e alcohol. 



^j^gjj' Alcohol and ether. 



Absolute alcohol. ' Dilute celloidin. 



Clear (c). Saturated celloidin. 



Paraffin. ' Imbed. 



Imbed ^^ P®^ ^^^^ alcohol, ( / ). 



Section. Section. 



Fix on slide, (d). »^tmn, [g). 



Xylol (e). Wash (Then glj'cerine will terminate 



Absolute alcohol. i^' "sed here). 



Stain (h). 95 per cent alcohol. 



'^ash' ■ Eosin-alcohol {g). 



Absolute alcohol. Oil of origanum cretici ; or oil of 



Xylol. ^lov^s (-/')• 



Balsam. Balsam. 



a. If sections are to be stained on the slide after imbedding in paraffin, 

 pass at once to absolute alcohol ; if the specimen is to be stained in toto, pass 

 to stain, etc. 



h. For staining in toto use Grenacher's borax-carmine, alum carmine or 

 Delafield's hicmatoxylin. For staining on the slide use either the above, or, 

 preferably, some one of the aniline colors. Specimens hardened in chromic 

 or osmic acid mixtures take carmine stains badly. 



c. Clear in either cedar oil, beech-wood creosote or chloroform. Avoid 

 clove oil, as it makes the paraffin granular. 



d. If the specimen has been stained m toto, use Schallibaum's collodion- 

 clove-oil fixative ; if sections are to lie stained on the slide, use Mayer's al- 

 bumen fixative. 



e. If the specimen was stained in toto, pass at once to balsam ; but if sec- 

 tions are to be stained, pass to absolute alcohol, stain, etc. 



/. After imbedding and previous to placing in 80 per cent alcohol, it is well 

 to place the block for a short time 1-2 hours in chloroform. This prevents 

 the formation of bubbles and makes the celloidin more uniform in consistency. 



g. For routine work use Delafield's ha-matoxylin and eosin-alcohol ; this 

 gives a double stain. Any other stain may be used, but some anilines color 

 the celloidin intensely. Ifother stain than hiematoxylin is used, the eosin- 

 alcohol may be omitted. 



/(. If it is desired to remove the celloidin from the section, clear the spe- 

 cimen in clove oil. "With delicate sections it should not be used. 



