252 STATE BOARD OF AGRICULTURE. 



condense large quantities of steam ; the perforated bottom, F, should 

 have numerous openings to permit the free upward movement of steam; 

 G, should be of wire netting. This causes a more uniform distribution 

 of steam, thereby preventing many breakages. 



As all factories are not supplied with apparatus for the production 

 of steam, a substitute may be made on the plan of an ordinary steam 

 cooker with an inch or two of water in the bottom. When this plan 

 is used sterilization begins when the steam begins to issue from the 

 openings. A thermometer placed in the opening, D, should register 

 210° F. 



Filling and Sterilizing. — In Fig. 2 the four jars, 1 to 4, are filled 

 with milk to the line, m, and the mouth of each filled with a dry firm 

 cotton plug. The plugs should, under all conditions, be kept dry. 

 Trouble may be anticipated in attempting to sterilize these thick glass 

 jars; but if a few precautions are taken there need be but few break- 

 ages. A shield (F in Fig. 1), placed so as to prevent hot water and 

 steam from striking the glass jars, and a wire gauge or window 

 screen for them to stand upon, insures almost any glass jar against 

 destruction by unequal heating. 



Fio. 3. 



The exact ])eriocl of time to heat cannot be given, for much depends 

 upon the steam pressure or upon the vigor with which the water is 

 boiled. Tests may be made with a thermometer to determine this 

 point. If kept at 210° F. for 30 or 40 minutes at each period for 

 four consecutive days, sterilization will be effected in case of small 

 quantities of milk. This, however, depends upon the amount of milk 

 in each bottle. 



A test for jars of milk supposed to be sterile may be made by plac- 

 ing them in a warm room, for a few days. If no visible change takes 

 place we are practically assured in saying that the milk is sterile. 



Inoculating and Developing. — The culture of lactic organisms may 

 be introduced as directions on the package indicate, but using every 

 precaution to prevent any of the material from coming in contact with 



