284 THE MILK SITUATION IN THE DISTRICT OF COLUMBIA. 



containing in the neighborhood of 3,000,000 bacteria shall be used, and the pas- 

 teurized product shall be collected as it flows from the cooling apparatus. 



All continuous pasteurizers shall be equipped with a feeding pipe which is so 

 constructed that the pasteurizer can not be fed in excess of its normal working 

 capacity ; that is, in excess of the working capacity of the machine at which 99 

 per cent of the bacteria are killed when the required amount of heat is applied. 



All continuous pasteurizers operated outside of the city limits for the produc- 

 tion of pasteurized milk and milk products to be sold in the city of Chicago 

 shall be equipped with an apparatus regulating automatically thje supply of 

 steam and heat, so as to correspond with and produce the required temperature 

 of the outflow of the pasteurized product. These automatic thermo regulators 

 shall be accurate and must be approved by the commissioner of health before 

 being installed. 



A recording apparatus shall be installed upon all continuous pasteurizers 

 operated within the city limits so as to record during operation the temperature 

 of the pasteurized product as it flows from the heater. The thermometer of 

 this recording apparatus must be accurate and kept immersed in the milk in 

 such a way that it is not exposed to escaping steam or other heat except the 

 heated milk. 



The records made by this recording thermometer must be accurate and made 

 in a chamber which is kept under lock and key in the control of the department 

 of health. 



The automatic thermo regulating and recording apparatus may be combined 

 into one instrument, and it is recommended that all pasteurizers be equipped 

 with both appliances or combination apparatus. 



(B) Held pasteurization. Whenever milk is held during' pasteurization in 

 such a manner that the process of pasteurizing is not a continuous one, namely, 

 a continuous flow of milk through the heating or heat-retaining chamber, 

 the process shall- be designated as " held pasteurization." Such methods 

 of pasteurization and pasteurization appliances or systems installed and used 

 shall be examined and approved by the commissioner of health, or his duly 

 appointed representatives, when all of the following requirements are fulfilled : 



1. When the pasteurized product shows that over 99 per cent of the bacteria 

 and all pathogenic bacteria contained in the raw product have been destroyed. 



2. When the mechanism of the pasteurizer or pasteurizing system is such that 

 the three important elements, namely, the temperature, time of exposure, and 

 the quantity of milk exposed at one time, can be readily kept under control and 

 observation by the department of health. 



3. When the following conditions are complied with : 



A uniform heating of 140 F. maintained for 20 minutes, 150 F. maintained 

 for 15 minutes, 155 F. maintained for 5 minutes, 160 F. maintained for 1^ 

 minutes, and 165 F. maintained for 1 minute. 



The time shall be calculated from the period that the entire quantity reaches 

 the required temperature. 



Rule 7. Cooling temperatures. The pasteurized product shall be cooled at 

 once to a temperature of 45 F. or less. This cooling shall be so conducted 

 that the pasteurized product is not exposed to the air or other contamination. 

 This cooling apparatus shall be so constructed that it can be readily cleansed 

 and sterilized. * 



OBDINANCES REQUIRING TUBERCULIN TEST OF ALL Cows SUPPLYING MILK AND 



MILK PRODUCTS. 



[Passed by the city council, July 13, 1908.] 

 MILK. 



Be it ordained "by the city council of the city of Chicago: 



Section 1. No milk, cream, buttermilk, or ice cream shall be sold, offered for 

 sale, exposed for sale, or kept with the intention of selling within the city of 

 Chicago after January 1, A. D. 1900, unless such milk or cream or the milk or 

 cream contained in buttermilk and ice cream, be obtained from cows that have 

 given a satisfactory negative tuberculin test within one year; the cows having 

 been satisfactorily tested shall be marked " tuberculin tested " and shall be 

 numbered and a certificate shall be filed with the division of milk inspection of 



