58 



ESSENTIALS OF BACTERIOLOGY. 



Human blood serum derived from placenta, serum from as- 

 citic fluid and ovarian cysts, is prepared in a similar manner 

 to the above. 



Blood Coagulum, suggested by the author, is the blood itself 

 (not the serum only) coagulated in test-tubes. It is dark brown 

 in color and allows some colonies of bacteria to be more visi- 

 ble. It requires less time to prepare, and is not so likely to 

 become contaminated as when the serum is used. 



FIG. 27. 



FIG. 28. 



Babe's incubator. Thermo-regulators. 



Loffler's Blood Serum Mixture (see p. 111). 



Peptone Solution. (Dunham's.) Sodium chlorid, 0.5; pep- 

 tone, 1 ; water, 100. Boil, filter, and sterilize. Useful to detect 

 presence of indol. 



Other Nutrient Media. Milk, urine, decoctions of various 

 fruits and plants, and lately for cultivating anaerobic bacteria, 

 eggs. 



