22, i Aguilar: Waters of Angat and Montalban Rivers 45 



also be employed to study its adaptability for use in various 

 industrial works. 



Adopting the methods followed by Chase Palmer, 2 the waters 

 taken from the six stations on Angat River, and the station on 

 Montalban River may be considered under Class 1. 



= The geochemical interpretation of water analysis, Bull. U S Geol 

 Survey 479 (1911) 11. 



The positive radicles determined in water analysis fall into three groups, 



Group A. Alkalies: sodium (Na'), potassium (K'), lithium (Li'). 



Group B. Earths: calcium (Ca"), magnesium (Mg"), iron (Fe"). 



Group C. Hydrogen (H'). 

 From these three groups, five special properties are possible, according 

 to the prevalence of the reacting values of the groups measured by the 

 sum of the reacting values of their members, namely: 



1. Primary salinity, or alkali salinity. 



2. Secondary salinity, or permanent hardness, 



3. Tertiary salinity, or acidity. 



4. Primary alkalinity, or permanent alkalinity. 



5. Secondary alkalinity, or temporary alkalinity. 



If the above groups A and B represent, respectively, the percentage 

 values of alkalies and earths and another group, D, the percentage values 

 of strong acids; namely, sulphates ("So*), chlorides ('CI), nitrates ('NO,), 

 any one of the following five conditions may occur, representing five dif- 

 ferent classes of water: 



Class 1. (D less than A.) 

 2D Primary salinity. 



2(A-D) Primary alkalinity. 



2B Secondary alkalinity. 



Class 2. (D equal to A.) 

 2A or 2D Primary salinity. 



2B Secondary alkalinity. 



Class 3. (D greater than A; less than A+B.) 

 2A Primary salinity. 



2(D — A) Secondary salinity. 



2(A + B-D) Secondary alkalinity. 



Class 4. (D equal to A+B.) 

 2A Primary salinity. 



2B Secondary salinity. 



Class 5. (D greater than A+B.) 

 2A Primary salinity. 



2B Secondary salinity. 



2(D-(A + B)) Tertiary salinity (acidity). 



