25 



M 



In Fig. 11, copied from Stoh- 

 maim's book is shown the ap- 

 paratus designed by Prof. Back- 

 haus (Germany) in which small 

 bottles of J quart are placed. 

 The bottles have a heavy, 

 smooth, slightly conical edge 

 on the neck in which there is a 

 sort of channel. The rubber 

 cover fits tightly at the top, but 

 when expanded by the steam 

 developed in heating it opens 

 up the channel and lets the 

 steam out. When cooling the 

 rubber is drawn closely to the 

 head of the bottle sealing it. 



The apparatus itself consists 

 of a cast-iron table P on a foot 

 piece with a hollow column B 

 in the center. On this are sev- 

 eral movable circular shelves 

 T. The steam is distributed 

 through holes in the column by 

 the pipe A, and also draws the cold air for cooling. Above 

 this is hung a cupola C, made of copper (counterbalanced by 

 E), which is let down on P and fastened steamtight by screws. 

 The guide K compels the cupola to come in the exact place so 

 as to let down the thermometer M into the cup G, which is 

 tilled with milk. The thermometer D shows the temperature 

 in the cupola, which is also provided with Manometer J, a 

 safety valve H and a blow off cock F. The cock H below the 

 table lets the condensed water off. 



A somewhat similar apparatus was used by Dr. E. N. 

 Eaton in Minneapolis, where he prepared an imitation of 

 human milk. He heated the milk, after modifying it, to about 

 212, then cooled it to 100 and left it for three hours for the 

 germs to develop, then reheated it and cooled the bottles by 

 placing them on a cement floor and spraying them with cold 

 water. Milk thus treated would keep for months. 



Some objections have been made to the use of rubber 

 stoppers, especially when they are new, they are liable to im- 



Fig. 11. 



