\V ASHING I'OWDKllS FOR DAIRY USE IS.i 



Results of Practical Tests on Washing Powders. 



* The figures in this column give the cubic centimeters of standard hard water (con- 

 taining the equivalent of 0.2 grams of calcium carbonate per liter) softened by 100 cc 

 of the standard solutions of the powders. 



t The figures in this column give the number of half seconds the slippery feel lasted 

 when tested as outlined above. These figures are all comparable, the low ones indi- 

 cating rapid rinsing. 



Further tests were conducted, which concerned the action of the typical 

 powders numbered 1, 2, 3, 6, 7, 8, 26, 23, 28, 31, A, B, and C, upon the metals 

 aluminum, copper, nickel, tin and zinc. The action of the powders upon th-^ 

 metals was carefully watched during the first day, and then obsened daily 

 thereafter. Strong alkali powders reacted immediately upon aluminum. 

 Other combinations reacted less readily and in reverse proportion to their 

 caustic strengths. Powders iiigh in soap content tended to l)]acken and tarnish 

 the metals. The tests were all allowed to stand for fifteen days. A summary 

 of the results is listed below: 



