In this paper we have collected the results of a considerable number of observations made on the distribution of the nonprotein sulphur of the blood of normal persons and of persons suffering from various pathologic conditions of the kidneys, heart and liver.
Experimental evidence is available which indicates1 that nonprotein sulphur exists in blood in the forms of at least three fractions, which appear to possess chemical properties similar to the several classes of sulphur compounds present in urine. Thus, there is present in blood a fraction designated as inorganic sulphate, which is precipitated by the addition of barium chloride to the deproteinized blood filtrate after suitable adjustment of the reaction of the latter. When the deproteinized blood filtrate is heated with acid, an additional precipitation with barium chloride results, and the difference between the value of the total sulphate so obtained and that of the inorganic sulphate is designated