'Total' ionic consideration of aqueous systems in biology

AGRONOMISTS and agricultural chemists in practice condone statements about applying a given weight 'of P₂O₅'; the only certainty then is that phosphorus pentoxide was not used, though a reader may infer that an unspecified phosphate is meant, either alone or mixed with much calcium sulphate. Statements, common in physiological literature, about treating a patient or a tissue with 'potassium' or 'Mg⁺⁺' are little more exact or informative for a research student or historian; nor are terms like 'ion-balance', or discussions of 'ions', when restricted to cations. Phenomena observed in solutions of complex salts are commonly attributed to 'effects of pH'; series of solutions 'adjusted to various pH-values', 'lacking NO₃', 'having extra Na', etc., are taken to be comparable, except for what is thought to be a single ionic variable.