42 BACTERIOLOGY 



Agar Colonies 



Characters as before. 



Stroke Cultures on Agar, Gelatin, Blood Serum, Potato 



(See II, p. 20.) 



Bouillon 



Reaction of medium. Liquid remsuns clear, or befcBrries opalescent or turbid. 



Surface growth, presence or absence ; membranous, coriaceous, farinaceous, 



gelatinous. Deposit, granular, flocculent, viscid, coherent. Odor. 



Milk 



Coagulated or not coagulated in . . . days at . . . ° C. Curd hard or soft, in 

 one mass or in fragments ; presence or absence of gas. Whey, presence 

 or absence, clear or turbid. If not coagulated, does or does not curdle 

 on boiling. 



Change of consistency or color ; presence or absence of peptones. 



Reaction in . . . days at . . . " C. 



Litmus Milk 

 Changes in color, at daily intervals of observation. 



Chemical Relations 



Fermentation tubes containing glucose, lactose, and saccharose bouillon. 



Relative growth in both arms. Presence or absence of gas. Amount of 



gas, measured daily. Total gas formed, in mm. of tube length. Amount 



after absorption with NaOH. The H CO, ratio. 

 Neutral bouillon containing 2 per cent of glucose. Determine titre at end of 



5 days at . . . ° C. 

 Neutral bouillon containing 2 per cent of lactose. Determination as before. 

 Neutral bouillon free from muscle sugar and containing 0.05 per cent of 



nitrate of soda. Determine titre at end of 5 days at . . . ° C. Test for 



ammonia. Presence of nitrites, indol, phenol, diastatic, and invertin 



ferments. 

 In neutral bouillon containing 2 per cent of glucose, and an excess of CaCO^, 



incubated for two weeks ; make analysis of organic acids in accordance 



with scheme proposed on p. 39. 



Pathogenesis 



Inoculation of fresh bouillon cultures into mice, guinea pigs, and rabbits. 



