GELATINE AGAR 193 



Wheat Bouillon (Gasperini). 



1. Weigh out and mix wheat flour, 150 grammes; magnesium 

 sulphate, 0.5 gramme; potassium nitrate, i gramme; glucose, 

 15 grammes. 



2. Dissolve the mixture in 1000 c.c. of water heated to 100 C. 



3. Filter through papier Chardin. 



4. Tube, and sterilise as for nutrient bouillon. 



Bread Paste. 



1. Grate stale bread finely on a bread-grater. 



2. Distribute the crumbs in sterile Erlenmeyer flasks, sufficient 

 to form a layer about one centimetre thick over the bottom of 

 each. 



3. Add as much distilled water as the crumbs will soak up, 

 but not enough to cover the bread. 



4. Plug the flasks and sterilise in the steamer at 100 C. for 

 thirty minutes on each of four consecutive days. 



Media for the Study of Parasitic Moulds. 



French Proof Agar (Sabouraud). 



1. Weigh out Chassaing's peptone, 10 grammes, and emulsify it 

 with 200 c.c. distilled water previously heated to 60 C. 



2. Weigh out powdered agar, 13 grammes, and emulsify with 

 200 c.c. cold distilled water. 



3. Mix the two emulsions and wash into a tared 2-litre flask 

 with 600 c.c. distilled water. 



4. Bubble live steam through the mixture for twenty minutes, 

 to dissolve the agar. 



5. Cool to 60 C. and clarify with egg as for nutrient agar 

 (vide page 168). 



6. Filter through Papier Chardin, using the hot-water funnel. 



7. Weigh out French maltose, 40 grammes, and dissolve in the 

 agar. 



8. Tube, and sterilise as for nutrient agar. 



English Proof Agar (Blaxall). Substitute Witte's peptone for 

 that of Chassaing, and proceed as for French proof agar. 



French Mannite Agar, Sabouraud. (For cultivation of Favus.) 

 Proceed exactly as in preparing French Proof agar vide supra 

 substituting Mannite (38 grammes) for maltose. 



Media for the Study of Milk Bacteria. 



Gelatine Agar. This medium is prepared by adding to nutrient 

 gelatine sufficient agar to ensure the solidity of the medium 

 when incubated at temperatures above 22 C. If it is intended 



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