ANALYSIS OF WATER AND INTERPRETATION OF RESULTS. 37 
As the figures representing the reacting values of the radicles have 
a greater chemical significance than those representing their weight, 
it is generally preferable to use the reacting values in comparing or 
studying analyses. Hence; statements in this report regarding the 
percentage of radicles present in waters refer to the percentage by 
reacting value, unless otherwise stated. 
PROPERTIES OF REACTION. 
Chase Palmer 1 has proposed a system for the classification and 
comparison of natural waters based on certain well-known properties 
of the solution as a whole, and his system is the one followed in this 
report. The writer has found this system very valuable, for it 
emphasizes certain differences between waters that are fundamental 
from the standpoint of the geologist and the industrial chemist, and 
is very convenient in the comparison of analyses. 
When different salts are dissolved in water they impart different 
qualities to the solution. A simple solution of sodium carbonate, for 
example, is soft and alkaline; one of sodium chloride is soft, but is 
neither alkaline nor acid, being neutral or saline, and one of calcium 
chloride is hard and saline. If the separate salt solutions are mixed, 
the resulting solution still has definite and determinable properties. 
For example, if 90 parts of sodium chloride and 10 parts of sodium 
carbonate are dissolved in water, the properties of the composite 
solution will be a summation of those of the solutions of the separate 
salts; in other words, the composite solution is characterized by 90 
per cent salinity and 10 per cent alkalinity. If to this solution cal¬ 
cium chloride is added, the percentage of these properties is altered, 
and a third property, hardness, is introduced. In a mixed solution 
of this kind it is no longer possible to state how much of each salt is 
present;, reactions have taken place and it is impossible to learn by 
analytical methods the order of the combinations that have resulted. 
Chemical analysis can determine only the amounts of the different 
radicles present. 
Although for the sake of simplicity the properties or qualities of 
the solution have in the preceding paragraph been ascribed to various 
salts, they are in reality due to the radicles themselves, uniformly 
distributed and held in balance; and inasmuch as the salts can not 
be determined they need not be considered further. • The general 
reactive properties of the solution may be readily deduced from the 
amounts of the radicles present, and in order to do this without 
undue complication those radicles which are similar chemically or 
associated geologically may conveniently be grouped together. Thus, 
the common bases may be grouped as alkalies (Na and K) and alka- 
i Palmer, Chase, Geochemical interpretation of water analyses: U. S. Geol. Survey Bull. 479, 1911. 
