Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: INTERPRETATION OF RESULTS. STATEMENT OF ANALYSIS. The composition of water is generally expressed in terms of a unit of weight in a definite volume of liquid, but much difference exists as to the standard selected. The decimal system is very largely employed, the proportions being expressed in milligrams per liter, nominally parts per million; or in centigrams per liter, nominally parts per hundred thousand. Not infrequently the figures are given in grains per imperial gallon of 70,000 grains, or the U. S. gallon of 58,328 grains. Much more rarely grains per quart, parts per thousand, per cents or other inconvenient ratios are employed. In this work the composition is always expressed in parts per million. This ratio is practically equivalent to milligrams per liter, except in cases of waters very rich in solids, since in such waters a liter weighs notably more than one million milligrams. Factors for converting the different ratios are given at the end of the book. From the analysis of a water it is rarely possible to ascertain the exact arrangement of the elements determined, but it is the custom to assume arrangements based upon the rule of associating in combination elements having the highest affinities, modifying this system by any inferences derived from the character or reactions of the water itself.It has been demonstrated that, even in the case of mixtures of salts producing no insoluble substances, partial interchange of the basylous and acidulous radicles takes place. In a solution of sodium chloride and potassium sulphate, both sodium sulphate and potassium chloride will be found, as well as both of the original salts. And when the conditions are rendered more complex by the addition of other substances, it is obviously impossible to determine the exact arran...