332 CITY MILK SUPPLY 



quantities of this were added to each of two tubes of lactose agar and 

 plated. For the test sample the same quantity of the dilution was put 

 into 5 c.c. of a solution of a weighed quantity of washing powder and 

 water, either at room temperature or 130F., and added to the lactose 

 agar at stated intervals. At first 1 gram of powder to 300 of water was 

 used but this was found to be too weak and so it was used in the propor- 

 tion of 1 gram to 150 of water which is at the rate of 1 Ib. of powder to 

 a little more than 17 gal. of water. The powders cost 5 to 6 cts. a pound. 

 Savogdram, Gold Dust and Pearline were tested and also sal soda or 

 washing soda, baking soda and caustic soda. The results indicate that 

 Savogdram, Gold Dust, Pearline and sal soda, in the proportion of 1 part 

 by weight to 150 parts of water at the temperature of 130F. and with an 

 exposure of 10 min. exert a notable disinfecting action. However, the 

 objection is made to sal soda that it deteriorates so rapidly that it can 

 be kept in stock only in small quantities. In contact with the air it 

 loses its water of crystallization and crumbles to a white powder that 

 actually interferes with washing. Baking soda which is often recom- 

 mended for cleaning nursing bottles has none of the properties of a soap 

 and no disinfecting action when used in the proportion of 1 part to 150 

 of water and only a slight one in the proportion of 1 to 8. It is suggested 

 that by neutralizing the sour smell in the bottle it deceives one into the 

 belief that it is a cleaner. The experiments with caustic soda indicate 

 that there was something besides the 20 per cent, of free alkali in the 

 washing powders that in a marked degree increased their antiseptic 

 properties. 



Wyandotte and tri-sodium phosphate are used in large quantities as 

 bottle cleansers but neither of these were tested in the experiments. 



Doane advises that in creameries washing powders be used in a hot 

 solution of 1 Ib. to 25 gal. The floors should first be washed with hot 

 water and then with the hot solution which should be allowed to dry off, 

 for the longer it remains the more effectively will it kill germs and check 

 odors. Tinware should be rinsed with cool or tepid water, then washed 

 in hot water after which the solution of washing powder should be added 

 and the utensil shaken to make sure that the solution touches every part. 

 So the whole stock should be treated and finally after 5 or 10 min. should 

 be rinsed with clean water. 



Washing powders deteriorate; so they should not be purchased in 

 large quantities. 



Sterilization of Bottles with Bleaching Powder. Whittaker and 

 Mohler suggest the sterilization of milk bottles by submerging them for 

 20 min. in a solution of calcium hypochlorite or bleaching powder con- 

 taining not over 10 parts per million of available chlorine or roughly 1 oz. 

 of powder to 100 gal. of water. In their experiments they obtained a 

 total average bacterial efficiency of over 99.9 per cent. An examination 



