ANALYSIS OF WATER AND INTERPRETATION OF RESULTS. 35 
Recalculation—Continued. 
Total Ca =1.11 +3.16 . 
Total Na =16.00+9.43 . 
Total S0 4 .. 
Total Cl. 
Total C0 3 =4.74 +12.27 
Grains per 
U. S. gallon. 
.... 4. 27 
.... 25.43 
.... 2.68 
.... 24.60 
.... 17.01 
73. 99 
Grains per Parts per 
U.S. gallon. million. 
Ca = 4. 27 X 17.1= 73.1 
Na =25. 43 X 17.1=435. 2 
S0 4 = 2. 68 X 17.1= 45. 9 
Cl =24.60 X 17.1=421.1 
C0 3 =17. 01 X 17.1=291.2 
73. 99 1,266. 5 
Proof: 73.99X17.1=1,266.5. 
REACTING VALUES. 
The statement of a water analysis in ionic form in parts per million 
shows numerically the relative proportions of the several radicles by 
physical weight, hi terms of gravity, and therefore is not a numerical 
representation of the water as a chemical reagent. A form of state¬ 
ment more convenient for study and comparison is that of reacting 
values, which shows numerically the relative proportions of the radi¬ 
cles by chemical weight, in terms of capacity for reaction. It is pos¬ 
sible to calculate either form of statement from the other, because for 
each radicle there is a fixed ratio between physical weight and capa¬ 
city for chemical reaction, though the ratios for the several radicles 
are different and the relation between the two forms of statement is 
therefore complex. The reacting value per unit weight of magnesium, 
for example, is much higher than that of sulphate, 10 parts of mag¬ 
nesium being chemically equivalent to 39.5 parts of sulphate. In 
order to understand the possibilities of reaction of the radicles in a 
water they should be considered as individuals acting together under 
the law of equivalent combining weights, each contributing its pro¬ 
portional share to the balance of the system. 
In order to translate an analysis from the ionic form into a form 
which expresses the chemical balance of the radicles, it is convenient 
to calculate the reacting values of the radicles. Stabler 1 has sug¬ 
gested that this be done by multiplying the weight of each radicle 
by its “ reaction coefficient/ ’ which he defines as the chemical react¬ 
ing power of a unit weight of the radicle. The reaction coefficient of 
a radicle is the ratio of the reaction capacity of one part of that 
radicle to the reaction capacity of eight parts of oxygen; in numerical 
value it is the valence of the radicle divided by its weight on the 
1 Stabler, Herman, The mineral analysis of water for industrial purposes and its interpretation by the 
engineer: Eng. News, vol. 60, p. 355, 1908: also chapter on the industrial application of water analyses in 
U. S. Geol. Survey Water-Supply Paper 274, pp. 165-181,1911. 
