| Show THE FIELD ASSAY OF WATER common sense Is the keynote of a recent paper entitled the field assay ot water written by sir marshall 0 leighton of the united states geological survey strange as it may seem this would appear to be a new note in the discussion of the subject for business like methods have not generally been adopted by those who have conducted chemical water surveys they have usually resorted to jong tedious and expensive processes to determine with absolute chemical accuracy the character and amoust of foreign constituents in rater inasmuch as approximate results in the analysis of water for hydro economic surveys are quite as serviceable as more accurate ones mr leighton holds that it Is wise and expedient and sensible to abandon the refined methods of analysis and adopt those which give reliable results in the shortest possible time tor the widest possible areas at the least possible expense conservatism he says als th e of science and one of the most commendable qualities of a chemist but an excess of conservatism ja sometimes almost as bad as a to illustrate the futility af pf the methods of testing water which are generally in vogue mr leighton discusses the faults of sanitary and inorganic analyses pis chief conclusions are 1 that the occasional isolated analysis of water is positively without value and fa that the inorganic constituents of a water should invariably be expressed as positive and negative ions as errors arise altogether too frequently from tho conventional vent ional methods of expression of rp suits among water there beems to be a general tendency to attack atta ck every water problem as though tao object were to brove its fitness or unfitness of drinking purposes whereas it Is oben el known that the water cannot be used ator domestic purposes and the problem is ot another character if care and discrimination were used in the selection of tests the work necessary in carrying on cherol surveys wight be djs 1 over a wider field results of more immediate use might be secured and the completion 0 a chemical survey would not ba postponed for the benefit 0 future generations As commercial methods servo useful purposes in the industrial world why would they not be efficient in water surveys inspired by these considerations the united states geological survey has investigated through its hydro econ amic division the of employing field methods for the determination mi 0 important characteristics of wafer these methods are described by hr leighton the apparatus employed is such as can be taken into the field and used on the spot thus permitting the study of large areas in a short time determinations are described for turbidity color total hard r ess normal carbonates bl ca total sulphates chlorine or tola chlorides ironald iro nand calcium mr lie eh tons brochure which is listed as water supply and irrigation paper no among the surveys publications should be accepted as a useful handbook |
