108 LIQUID CULTIVATING MEDIA. 



more suitable for the growth of organisms, by the addition of one per 

 cent, of albumen peptone before the initial neutralisation and filtering 



are carried out. 



Buchner's Fluid. 



52. Amongst the nutrient animal infusions, that recommended by 

 Buchner will be found of great value. It consists of — 



Liebig's meat extract, . . .10 parts. 



Albumen peptone, . . . . 8 „ 



Distilled water, .... 1000 „ 



Before it is used it must be sterilised and incubated under observa- 

 tion for a week, as has been already described. 



A similar peptonised liquid can be even more easily procured by 

 using Darby's fluid meat (peptonised) in a half per cent, solution : — 



Darby's fluid meat. .... 5 parts. 



Distilled water, .... 1000 „ 



Sterilise by steaming, and incubate under observation before use. 



Urine. 



53. Urine passed into sterile flasks with antiseptic precautions (use 

 of spray, careful purification of meatus) does not become alkaline, as it 

 would do if exposed under ordinary conditions to the air. This is 

 equivalent to stating that it remains sterile ; and it forms, without 

 further preparation, an admirable soil for several kinds of fungi 

 (moulds) : but from its slightly acid reaction, it is not, in the first 

 place, so well adapted to the growth of the cleft fungi (bacteria). 

 Should, however, one of the latter {Micrococcus area, Cohn) once 

 establish itself in the urine, it gives rise to the ammoniacal fermenta- 

 tion, and prepares the way for the growth of its congeners by render- 

 ing the liquid alkaline ; whilst the moulds, overpowered by the rapid 

 growth of cleft fungi, soon lose their vitality, and are disintegrated. 

 If urine cannot be collected with the precautions named, it should 

 be placed in sterile flasks, and treated as any of the animal infusions 

 above described, before it is used for experiments. 



Milk. 



54. If collected in sterile flasks with careful aseptic precautions 

 (pure air, or spray, and careful purification of teats l ) milk will remain 



"Antiseptic Surgery," Watson Cheyne, pp. 38-39, 1881. 



