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To prepare the solution for this determination, which should be approximately 0.05 N, dissolve about 5 grams of potassium thiocyanate, or 4 grams of ammonium thiocyanate, in a small amount of water; dilute this solution to 1000 cc. in a liter bottle and mix as usual. About 5 cc. of this solution should be used as an indicator.
Cover the solution with a watch-glass; allow it to stand until cool, or preferably over night. Filter the solution through a layer of asbestos. In neutral solutions the reduction of the permanganate is less complete, and, under these conditions, two gram-molecular weights of KMnO will furnish only 48 grams of oxygen.
Sulphide sulphur was determined in a sample of reduced barium sulphate by the evolution method, in which the sulphur was evolved as hydrogen sulphide and was passed into CdCl solution, the acidified precipitate being titrated with iodine and thiosulphate. Sample, 5.076 grams; cc. I = 20.83; cc. Na S O = 12.37; 43.45 cc. Na S O = 43.42 cc. I ; 8.06 cc. KMnO = 44.66 cc. Na S O ; 28.87 cc.
At one side of the concretion a piece had been broken off exposing an incisor tooth which represented the nucleus of the formation. Manasse recently reported the case of a man of forty-four whose stomach contained a stone weighing 75 grams. He was a joiner and, it was supposed, habitually drank some alcoholic solution of shellac used in his trade.
The sublimed iodine is then dried by placing it in a closed container over concentrated sulphuric acid. It may then be weighed in a stoppered weighing-tube and dissolved in a solution of potassium iodide in a stoppered flask to prevent loss of iodine by volatilization. About 18 grams of the iodide and twelve grams of iodine per liter are required for an approximately tenth-normal solution.
Although, therefore, the iodine contains no oxygen, the two atoms of iodine have, in effect, brought about the addition of one oxygen atoms to the sulphur atoms. By a similar course of reasoning the conclusion is reached that the normal solution of sodium thiosulphate should contain, per liter, its molecular weight in grams.
As the thiosulphate in crystalline form has the formula Na S O .5H O, this weight is 248.12 grams. Tenth-normal or hundredth-normal solutions are generally used. !Approximate Strength, 0.1 N! PROCEDURE. Weigh out on the rough balances 13 grams of commercial iodine. Place it in a mortar with 18 grams of potassium iodide and triturate with small portions of water until all is dissolved.
Particularly was this treatment advocated by Cantonnet in the administration of daily doses of 3 grams of chlorid of sodium, preceded, of course, by a careful urinary examination and the estimation of the amount of urine and its contained chlorids.
Death due to bilateral ptthisis with tuberculosis of intestines and mesenteric glands, emaciation. It is noteworthy that the brain weighed but 1038 grams. Dr. W. L. Worcester's microscopic examination showed acute nerve cell changes probably of the type of axonal reactions.
A normal solution of an oxidizing agent should, therefore, contain that amount per liter which is equivalent in oxidizing power to 8 grams of oxygen; a normal reducing solution must be equivalent in reducing power to 1 gram of hydrogen. In order to determine what the amount per liter will be it is necessary to know how the reagents enter into reaction.
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