THE GLYCERIN METHOD 103 



best, and it should consist of two coats, for a crack would seldom 

 appear at the same place in both coats. A good shape and thickness 

 for a ring are shown in Figure 19. 



The following is a summarj^ of the foregoing processes: 



1. Fix in chromo-acetic-osmic acid, 24 hours. 



2. Wash in water, 24 hours. 



3. Alcohols, 2^-85 per cent. 



4. Alcohols, 85-2| per cent. 



5. Wash in water, 30 minutes. 



6. Iron-alum, 4 hours. 



7. Wash in water, 30 minutes. 



8. Haematoxylin, | per cent, 24 hours. 



9. Wash in water, 30 minutes. 



10. Iron-alum until the stain is satisfactory. 



11. Wash in water, 30 minutes. 



12. Ten per cent glycerin. 



13. Mount and seal. 



14. Label. 



The times just given may seem unnecessarily long, but one can al- 

 ways do something between times. The following summary, taken 

 from the fourth edition of this book, is much shorter and it gives good 

 results, unless you compare the slides with those made by the longer 

 schedule, just as ordinary glass looks good, unless you put it side by 

 side with plate glass : 



1. Fix in cln-omo-acetic-osmic acid, 24-48 hours. 



2. Wash in water, 24 hours. Bleach and wash in water. 



3. Iron solution, 2 hours. 



4. Wash in water, 10 minutes. 



5. One-half per cent haematoxylin, 3-24 hours. 



6. Wash in water, 10 minutes. 



7. Iron solution until stain is right. 



8. Wash in water, 1 hour. 



9. Ten per cent glycerin. 

 10. Mount and seal. 



If material has been fixed in formalin, it should be washed in water 

 for 30 minutes before starting with stage 3 of the long schedule, or the 

 first iron-alum of the short schedule. Material preserved in formalin- 

 alcohol-acetic acid, with 70 per cent alcohol, should be run down to 

 water before staining. If the alcohol is only 50 per cent, put the 



