18 
METHOD OF MAKING FROZEN SECTIONS. (Wright.) 
I 
1 . 'Place tissue not over 5 mm. thick in 10 per cent formalin for two or more hours. I 
2. Wash in water. , 
3. Freeze with CO 2 or ether. 
4. Cut frozen sections. 
5. Float sections in normal salt solution and then on slide. 
6. Cover section with cigarette paper, then with blotter moistened with 95 per cent 
alcohol. Press. Remove papers. 
7. Cover with absolute alcohol thirty seconds. Drain. 
8. Flow over the section and adjacent parts of the slide a thin solution of celloidin 
in equal parts of absolute alcohol and ether. Drain off immediately. The 
celloidin should form a coating so thin as to be invisible. 
9. Flood the slide with 95 per cent alcohol and then immerse in water. This hard- 
ens the film. 
10. Stain. 
11. Dehydrate. 
12. Clear with oil origanum. ; 
13. Mount in Canada balsam. 
