76 PHARMACEUTICAL BACTERIOLOGY. 



however, be stained by the usual acid-fast or acid-proof methods, care being 

 observed in decolorizing. Stain with hot carbol-fuchsin for a few minutes, 

 wash, and decolorize quickly with 3 per cent, hydrochloric acid in 95 per cent, 

 alcohol, and then use a contrast stain, as gentian-violet or methylene blue. 

 The red spores will then appear in the violet or blue frame. 



9. Capsule Staining. 



The gelatinous capsule of microbes is also stained with great difficulty, 

 and requires special methods and experience to yield anything like satisfactory 

 results. The methods of Welch and Hiss are quite satisfactory. The cap- 

 sule is, however, generally visible without any staining because of the light 

 contrast that naturally exists. Certain substances, as glacial acetic acid 

 (Welch method), cause the capsule to enlarge and take up the stain more 

 readily. Certain staining methods bring out the capsule of certain mi- 

 crobes, as, for example, the Gram method as applied to pneumonia sputum. 



The Muir method is perhaps the best for capsule staining. It is as 

 follows: 



1. Stain in carbol-fuchsin for one-half minute, with gentle heat. 



2. Wash lightly in alcohol (95 per cent.). 



3. Wash well in water. 



4. Flood with mordant of 



Sat. Aq. Sol. Mercuric Chlor., 2 c.c. 



Tannic Acid (20 per cent. Aq. Sol.), 2 c.c. 



Sat. Aq. Sol. Potassium Alum, 5 c.c. 



5. Wash in water. 



6. Wash in 95 per cent, alcohol, one minute. 



7. Wash in water. 



8. Stain with methylene blue for one-half minute. 



9. Dehydrate in alcohol. 



10. Clear in xylene, and mount in Canada balsam. 



There are numerous other special stains and special staining methods, 

 which need not be mentioned here. Should the pharmacist be called upon 

 to prepare any of these, he will find full particulars in any standard work 

 on medical bacteriology. 



9. Studying Bacteria. 



The complete study of any one species of microbe with a view to deter- 

 mining its identity is a long and tedious process. It involves a study of the 

 organism in its natural element and in artificial culture media, and its 

 behavior in animal inoculation tests, etc. Special apparatus, experimental 

 animals (as rats, mice, guinea-pigs, dogs, etc.), and technical experience and 



