Bário em Braun-Blanquet (1932)

Determination of Sulphates.—A soil extract is made with slightly acidulated water (HCl 1 per cent). In the filtrate the sulphate is precipitated with barium chloride, BaCl₂. The barium sulphate, BaSO₄, is washed carefully and dried. Its weight, multiplied by 0.4114, gives the amount of sulphuric acid: (1g.BaSO₄ = 0.4115g.SO₄) (see also Wiegner, 1926, p. 39). (Braun-Blanquet 1932:203)

BRAUN-BLANQUET, Josias. 1932. Plant sociology: the study of plant communities. (Trans.: George D. Fuller; Henry S. Conard) New York: McGraw-Hill Book Company.