XIII, A, 1 Heisc and Behrman: Water Analysis in Field 13 



the original water, that is, before it was diluted with sulphuric 

 acid, phenolphthalein, and alcoholic potash. Then the total 

 hardness is computed from the value and number of the pellets 

 used. 



For example, let us suppose that the original volume of 100 

 cubic centimeters had been diluted to 104.5 cubic centimeters 

 before titration with the palmitate pellets, each equivalent to 

 1.80 milligrams of calcium carbonate. Obviously the 48.5 cubic 

 centimeters used for the determination are equal to 



48AXi00 



104.5 -^^-^ 



cubic centimeters of the original water. 



Therefore the total hardness would be derived from the 

 expression 



1,000 X 4 X 1.80 

 46.4 



Or, using the data above, we may represent the entire calcula- 

 tion in one line as follows : Total hardness (as parts per million 

 calcium carbonate) is equal to 



10X104.5 X4X l-80 _-,;,^ . 

 4875 -- ^^^• 



Total solids may be also estimated with the aid of Dole's 

 formula,^ slightly modified. For Philippine ground waters the 

 following will be found satisfactory: 



100 + normal carbonates (as NasCOs) + bicarbonates (as CaCOs) + 1.7 

 SO, + 1.6 CI. 



Estimated encrustants are calculated (for clear water) from 

 Dole's formula : ® 



Estimated encrustants= 



Bicarbonate alkalinity (as CaCOs) 

 - CaSO., + total hardness (as CaCOa) 



Assuming the sulphates to be present as calcium sulphate, 

 the CaSO^ in the above formula may be calculated as 1.7 SO3. 

 In this form the formula is available for field work. 



Classification for boiler use is based upon the amount of 

 estimated encrustants, as given by the American Railway En- 

 gineers' Maintenance of Way Association : ^ 



"Dole, R. B., U. S. Geol. Surv., Water Supply Paper (1916), No. 399, 

 304. 



' U. S. Geol. Surv., Water Supply Paper (1910), No. 254, 232. 

 ' Proc. Am. Ry. Eng. & Maint. Way Assoc. (1904), 5, 595. 



