42 METHODS OF CULTIVATION OF BACTERIA. 



suitable, it has the disadvantage for certain purposes of 

 containing a larger proportion of fermentable sugar. The 

 flesh must be freed from fat, and finely minced. To a 

 pound of mince add 1000 c.c. distilled water, and mix 

 thoroughly in a shallow dish. Set aside in a cool place for 

 twenty-four hours. Skim off any fat present, removing the 

 last traces by stroking the surface of the fluid with pieces 

 of filter paper. Place a clean linen cloth over the mouth 

 of a large filter funnel, and strain the fluid through it into 

 a flask. Pour the minced meat into the cloth, and gather- 

 ing up the edges of the latter in the 

 left hand, squeeze out the juice still 

 held back in the contained meat. 

 Finish this expression by putting the 

 cloth and its contents into a meat 

 press (Fig. 6), similar to that used 

 by pharmacists in preparing extracts ; 

 thus squeeze out the last drops. The 

 resulting sanguineous fluid contains 

 the soluble albumins of the meat, 

 the soluble salts, extractives, and 

 colouring matter, chiefly haemoglobin. 



FlG 6 Meat ss It is now boiled thoroughly for two 



hours, by which process the albumins 



coagulable by heat are coagulated. Strain now through a 

 clean cloth, boil for another half-hour, and filter through white 

 Swedish filter paper (best, C. Schleicher u. Schull, No. 595). 

 Make up to 1000 c.c. with distilled water. The resulting 

 fluid ought to be quite transparent, of a yellowish colour 

 without any red tint. If there is any redness, the fluid 

 must be reboiled and filtered till this colour disappears, 

 otherwise in the later stages it will become opalescent. A 

 large quantity of the extract may be made at a time, and 

 what is not immediately required is put into a large flask, 

 the neck plugged with cotton wool, and the whole sterilised 

 by methods B (2) or (3). This extract contains very little 

 albuminous matter, and consists chiefly of the "soluble salts 

 of the muscle, certain extractives, and altered colouring 



