WASHING POWDERS FOR DAIRY USE 181 



Ii(>\\ders were subjected to laboratory- and i)}ant tests for efficiency of per- 

 l<irniance in the various cleaning operations. 



riie results of the chemical analyses are listed below. If the figures given 

 tif not total 100 per cent tlie reader must bear in mind that the water content 

 ni.iy be verj'" high in some cases (15 per cent or over), and many ingredients 

 net determined but listed later may have been present. Chapin in some of 

 his work, (3) leaves undeteniiined quantities as high as 26 per cent. 



Analyses of Washing Powders. 



It may be observed from this table that many of the powders were of very 

 nearly identical composition, yet great variations are also shown. The 

 Ipovvders may be classified into four main groups: those containing pure car- 

 bonate, those containing tri-sodium phosphate, those containing free caustic 



