— 148— 



A small drop of the allninien fixative is placed on a 

 slide, and spread in a veri/ thin layer with a clean glass rod, 

 or better, with a dry and clean finger. The section is now 

 placed on the albumen fixative, and pressed to the slide. 

 If the section is st(n)ied, the paraffin is melted by holding 

 the slide or cover glass over an alcohol flame, or by plac- 

 ing them on a water bath, until tin- i):ir:iflin ]>egins to niflt ; 

 then cover with :t few drops of oil dI' turpentine, which dis- 

 solves the paraffin; remove excess of oil with filter paper, 

 and mount in balsam. If it is desired to stain the sections 

 after they are fixed to the slide? or cover glass, the follow- 

 ing steps are taken to remove the paralliu : — 



1. Heat quickly over the flame until the parnflin be- 

 gins to melt. 



2. Place the slide or cover glass into toluol or xylol 

 until the parailin is dissolved. 



3. Transfer to absohite alcohol for 3 to 5 minutes; 

 this removes the toluol or xylol. 



4. Transfer to 95% alcohol for .5 iiiinutes. 



5. Transfer to 70% alcohol for several minutes. 



6. Remove alcohol l>y placing slide or cover into dis- 

 tilled water. Sections can now be stained. 



It is often quite difficult to remove folds from paraffin 

 sections (especially if sections are large) l)efore fixing 

 to the slide or cover glass with albumen fixative; the 

 author has used with success this simple method ; 



An evaporating dish is partly filled with distilled 

 water; on this the sections are placed. The water is now 

 slowly heated by holding the evaporating dish over an 

 alcohol flame. It will be noticed that as the temperature 

 of the water is raised, the ])araffin in and about the sec- 

 tions begins to soften, and the sections spread out over the 

 surface of the water. The water is heated until all folds 

 are obliterated. Care should be taken not to get the water 

 hot enough to melt the paraffin. A slide or cover glass, on 

 which a thin layer of the albumen fixative is spread, is 

 now passed under one of the sections; on it the section is 

 caught and withdrawn from the water. Allow all the 

 water to evaporate, this usually takes 8 to 12 hours, at the 



