CH. X] 



PARAFFIN METHOD 



303 



come off in the many processes of staining, and if one has many 

 sections on a slide some of them may become loosened. Tp avoid 

 this the sections are covered with a delicate layer of collodion, 

 which holds them down to the slide. The early method was to use 

 a soft brush and paint a thin film over the dried sections before they 

 were deparaffined. Now the sections are deparaffined, and then 

 after draining the xylene from the slide, 10-15 seconds, it is put 

 into a bottle containing y\% collodion ( 395). In a minute or 

 more the collodion displaces the xylene and penetrates the sections 

 and forms a delicate veil over their free surface. No harm is done 

 by leaving the sections in the collodion a considerable time, but a 

 minute or two is sufficient. The slide is removed, allowed to drain 

 for half a minute, and then put into a jar of 67% alcohol (Fig. 222). 

 The alcohol fixes the collodion and removes the ether. As the 67% 

 alcohol does not hurt the tissue it may stay in the jar a day or more 

 if desired, but half an hour suffices. 



Steps in Order for the Paraffin Method. 439, 450, 461- 

 471. 



Name 



No. 



Animal 



Date ;' 



Fixer 



Time of fix 



Washed in water 



67",, ale 82% ale 



Decalc. $ 398 67, 82% ale.. 



In toto stain 



Washed in 



67",, ale 82% ale 



95",, ale. and eosin 



Absl. ale. Cedar oil.. 



Infill. 



Temp, bath Imbed, in. 



Sections cut //'s 



Temp, room 



Stains __ 



Mtd. in 



Remarks . 



