5 
0.1 cc. of 1 per cent. solution of lead acetate. This produces a yellow precipitate 
which is blackened if H.S is formed. The solutions should be neutral. Difco 
peptone was used. 
(c) Clam media. 
1 part clam meat+2 parts sea water. 
3. MEDIA FOR DIFFERENTIATION. 
Beef peptone agar. 
Beef peptone broth+1.5 per cent. of Japanese agar. 
Beef peptone gelatin. 
Prepared as already described. 
Beef peptone Broth. Two kinds were used. 
(1) As described above. 
(2) Difco nutrient broth 0.8 per cent. 
Sodium chloride 0.8 per cent. 
Distilled water. 
Peptone water (Dunham’s). 
Peptone I per cent. 
Sodium chloride 0.5 per cent. 
Distilled water. 
Nitrate Broth. 
Dunham’s peptone water+0.5 per cent. K NOs. 
Potato. 
Wedges were soaked 30 minutes in 1 per cent. sodium carbonate, rinsed 
thoroughly in distilled water and sterilized. 
Litmus Milk. 
Klim adjusted to +1 reaction and sterile litmus solution added. 
Fermentation Media. 
Dunham’s peptone water was used as a foundation. 
Dextrose Medium. 
Peptone water +2 per cent. dextrose. 
Lactose Medium. 
Peptone water +2 per cent. lactose. 
Saccharose Medium. 
Peptone water +2 per cenit: saccharose. 
Glycerin Medium. 
Peptone water +6 per cent. glycerin. 
To each of these 2 per cent. Andrade indicator was added. 
Mannit protein-free broth. Mannit protein-free agar. 
Mannit 15.0 grams 1.5 per cent. washed 
K, HPO, OPO agar added to mannit 
Meg SO; Os 2 rare solution prepared as 
Na Cl ORs described. 
C4 S04 Ook a 
Car C0; 50 4, 
10% Fe C1 solution 1.0 drop. 
Distilled water, 1,000 cc 
