214 SPECIAL MEDIA 



D^plococcus Pneumonias. 



Blood Agar (Washbourn). 



1. Melt up several tubes of nutrient agar (vide page 167) and 

 allow them to solidify in the oblique position. 



2. Place the tubes, in the horizontal position, in the "hot" 

 incubator for forty-eight hours, to evaporate off some of the 

 condensation water. 



3. Kill a small rabbit with chloroform and nail it out on a 

 "board (as for a necropsy) . Moisten the .hair thoroughly with 2 

 per cent, solution of lysol. 



4. Sterilise several pairs of forceps, scissors, etc., by boiling. 



5. Reflect the skin over the thorax with sterile instruments. 



6. Open the thoracic cavity by the aid of a fresh set of sterile 

 instruments. 



7. Open the pericardium with another set of sterile instruments. 



8. Sear the surface of the left ventricle with a red-hot iron 

 and remove fluid blood from the heart by means of sterile pipettes 

 (e. g., those shown in Fig. 13, c). 



9. Deliver a small quantity of the blood on the slanted surface 

 of the agar in each of the tubes, and allow it to run over the 

 entire surface of the medium. 



10. Place the tubes in the slanting position and allow the 

 blood to coagulate. 



11. Return the "blood agar" to the hot incubator for forty- 

 eight hours and eliminate any contaminated tubes. Store the 

 remainder for future use. 



Media for the Study of Mouth Bacteria Generally. 



Potato Gelatine (Goadby). 



1. Prepare glycerine potato broth (see page 203, sections i to 5). 



2. Add 10 per cent, gelatine to the potato decoction and 

 bubble live steam through the mixture for ten minutes. 



3. Estimate the reaction; adjust the reaction of the medium 

 to +5. 



4. Cool the medium to below 60 C., clarify with egg as for 

 nutrient gelatine. 



5. Filter through papier Chardin. 



6. Tube, and sterilise as for nutrient gelatine. 



Media for the Study of Protozoa. 



Tissue Medium (Noguchi). For spirochcetes (cultivations must be 

 grown anaerobically} . 



1. Plug and sterilise test-tubes 20 X 2 cm. 



2. Kill a small rabbit with chloroform vapour. Open the abdo- 



