CONTAMINATION OF FOODS U7 



it is made. Woodenware can be cleaned less easily and less 

 thoroughly than can metal vessels. Again, if the utensil is 

 so constructed that joints and angles exist which can not be 

 readily reached in the cleaning by the cloth or brush, it will 

 be difficult to remove accumulations of organic matter. The 

 sharp angles encountered in milk-cans, and the open joints 

 that are found in the cheaper grades of tinware, make such 

 utensils difficult to clean. 



The condition of the utensil is another factor that deter- 

 mines the ease with which the cleaning process is carried 

 out. The smooth surface of a new tin vessel is much .easier 

 to clean than that of a rusted and dented utensil. Such 

 complicated utensils as milking-machines and cream-sepa- 

 rators are difficult to keep in a sanitary condition. The 

 rubber tubes tlmt conduct the milk from the teat-cups to 

 the receiving can of the machine can not be entirely freed 

 from milk, and it is impossible to dry them. In order to 

 avoid a large amount of contamination from the tubes, it is 

 necessary to place them in an antiseptic solution in such a 

 manner that they shall be entirely filled with the solution 

 and not partially filled with entrapped air. No solution 

 has been found entirely satisfactory. If a few pieces of 

 fresh quick or stone lime are kept in the tank in which the 

 rubber parts of the machine are to be placed, the alkalinity 

 of the solution will be such as to prevent bacterial growth. 

 A saturated solution of common salt may also be used, but 

 this will not completely prevent the growth of bacteria. 

 Certain kinds will grow very slowly therein. 



The addition of a small amount of a solution of calcium 

 hypochlorite or bleaching powder to the brine will destroy 

 the bacteria. The addition of one part of a solution ob- 

 tained by stirring one pound of bleaching powder in one 

 gallon of water, and allowing the insoluble portion to settle, 

 to two hundred parts of the brine at semi-weekly intervals, 



