APPENDIX. 



MEDIA MAKING. 



Extract from the Report of the Committee on Standard Methods of 

 Water Analysis, igoj. 



In view of the marked influence upon bacteriological 

 reactions of variations in culture media caused by differ- 

 ences ,both in ingredients and in technique of prepara- 

 tion, it is necessary that imiform methods be used in order 

 to obtain comparable data. In specifying the various in- 

 gredients used in culture media it is the intention of the 

 committee that they shall be uniform in quality, but it 

 is not the intention that the recommendations as to ingre- 

 dients and technical manipulations shall stand in the 

 way of true progress as to improvements. When, how- 

 ever, improved or modified methods are used, the varia- 

 tions from the standard methods shall be plainly set 

 forth together with the reasons for the modifications. 



INGREDIENTS. 



Distilled water shall be used in the preparation of 

 standard culture media. 



■ Infusions of fresh lean meat, and not meat extract, 

 shall be used as the basis of various media. 



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