ANALYSIS OF WATER AND INTERPRETATION OF RESULTS. 33 
ascertain by the ordinary methods of analysis what compounds, if 
an y> oxist in the solution; his work is limited for the most part to 
the determination of the roots or portions of compounds that are 
known as radicles. In fact, present chemical knowledge indicates 
that a salt dissolved in water largely ceases to exist as an actual com¬ 
pound; according to the ionic theory it becomes partly dissociated 
into its component radicles, which become electrically charged or 
ionized, and it participates in chemical reactions only in so far as it 
is ionized. Even if it were held that the radicles of dissolved salts 
are actually combined it is a chemical and mathematical impossi¬ 
bility to ascertain by analysis to what extent a given base is combined 
with a given acid. 1 Despite this condition it is common practice to 
report hypothetical combinations by several methods of calculation, 
founded on different theories or devised from different points of view, 
in accordance with wliich the radicles are apportioned to one another. 
As a result of this difference of opinion it is impossible to compare the 
results of one chemist with those of another until the analytical data 
have been reduced to a statement of all the radicles actually deter¬ 
mined. It has been shown that the character of a water for industrial 
purposes, its fitness for domestic use, and its relation to its environ¬ 
ment can be defined without recourse to hypothetical combinations. 2 
As there appears to be no valid reason for reporting analyses in 
hypothetical combinations and as it is impossible to compare analyses 
so reported by different chemists, the analyses in this report have been 
calculated to ionic form in order to show the amounts of the radicles 
actually found by the analyst. They have also been calculated to 
parts per million, the proportion most suitable for comparison, in 
order to avoid confusion due to the use of different units, such as 
grams per United States gallon, percentage, and parts per hundred 
thousand. 
For the convenience of those who may desire to transform results 
into parts per million it may be stated that 1 grain per United States 
gallon is equivalent to 17.1 parts per million, 1 grain per imperial 
gallon to 14.3 parts per million, 1 part per hundred thousand to 10 
parts per million, 1 gram per kilogram to 1,000 parts per million by 
weight, and 1 gram per liter to 1,000 parts (weight) per million 
(volume). All the analyses in this report made by the Geological 
Survey are stated in parts by weight per million volume, and the 
remaining analyses are' believed to be also stated in this way. 
1 Dole, R. B., Hypothetical combinations in water analysis: Jour. Ind. and Eng. Chemistry, vol. 6, 
pp. 710-721, 1914. 
2 Stabler, Herman, The mineral analysis of water for industrial purposes and its interpretation by the 
engineer: Eng. News, vol. 60, p. 355, 1908; Some stream waters of the western United States, with chapters 
on sediment carried by the Rio Grande and the ind ustrial application of water analyses: U. S. Geol. Survey 
Water-Supply Paper 274, pp. 165-181,1911. Clarke, F. W., The data of geochemistry, 3d ed.: U. S. GeoL 
Survey Bull. 616, pp. 59-61,1916. See also U. S. Geol. Survey Water-Supply Paper 254, pp. 233-258,1910, 
and Water-Supply Paper 259, pp. 173-197, 1912. 
60439°—Bull. 653—17-3 
