Examination of Water for Sanitary and Technic Purposes (Paperback)

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 used. 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. The figures are often given in grains per imperial gallon of 70,000 grains, or the U. S. gallon of 58328 grains. In this work the composition is always expressed in milligrams per liter. This ratio is practically equivalent to parts per million, except in case of water very rich in solids, a liter of which will weigh 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 chlorid and potassium sulfatesodium sulfate and potassium chlorid will be found, as well as the original salts. When the conditions are rendered more complex by the addition of other substances, it is obviously impossible to determine the exact arrangement. In view of these facts, it is preferable to express the composition of a water by the proportion of each element or radicle present. In this way a ...