'i-68 IiUdligence and Miscellaneous Jrtidcs. 



thofl proposed by M. Fan (tome xi.) for the preparation of iodide 

 of potassium. Decompose carefully a solution of hydrosulphuret of 

 barylesbv tincture of iodine; forthis purpose, after having treated some 

 sulphate of barytes, finely powdered, with muriatic acid, and washed it, 

 it is to be mixed with about one-sixth of some easily decomposa- 

 ble organic body, as starch, sugar, oil, kc: the residuum is to be 

 strongly calcined, treated with pure boiling water, then quickly fil- 

 tered or decanted without the contact of the air. A strong alcoholic 

 solution of iodine is then to be j)oured into it until a milky white pre- 

 cipitate ceases to be formed 3 then filter and evaporate, as will pre- 

 sently be mentioned. 



On each addition of the tincture of iodine, a white precipitate is 

 formed, which disappears when the hydrosulphuret of barytes is in 

 excess, and which then produces a greenish tint j the sulphur depo- 

 sited unquestionably dissolves in the salt and gives it another degree 

 of sulphuration. 



When the vvished-for point is arrived at, the filtered liquor is limpid and 

 colourless; and the alcohol must be separated by distillation. Evapo- 

 ration is then to be carried on nearly to dryness, a little water is to 

 be added, and the solution is to be quickly filtered through unsized 

 paper ; this solution is then to be evaporated in a flask, and without 

 the presence of the air of the atmosphere ; the flask is to be broken 

 after crystallization, and the iodide is obtained in a grayish white mass 

 of silky crystals. This salt is very deliquescent and soluble in alcohol, 

 and precipitated by the sulphates ; when heated and ex|)osed to the 

 air, it gives out iodine ; when put in contact with sized paper, it is 

 partly decomposed, and blues the starch which exists in it. When the 

 evaporation is not carried too far, the crystals are more distinct prisms. 



The iodide of barium obtained by this process, dried in a tube with- 

 out the contact of air, yielded by analysis proportions in accordance 



with theory : Barium 3.5- 1 7 



Iodine 6483 



100-00 

 Iodide of strontium was obtained in a similar manner ; its colour 

 was yellower than that of barium.— /6id. 



CHEMICAL TATHOLOGY OF CHOLERA. 



Dr. O'Shaughnessy has published a mo-^t elaborate examination of 

 the composition of the blood, and of the fsecal matters in this terrific 

 malady ; and deduced from his results, pathologic and therapeutic 

 inferences equally interesting and useful. 



In his experiments, (which accprd perfectly with those made by 

 Foy at Warsaw, and by Rose and Wittstock at Berlin,) he found the 

 principal alterations of the bloodito consist in a great diminution in 

 quantity of the water, so that theiquantities of the organic principles 

 are relatively much augmented ; the serum being small in quantity, 

 imperfectly separated, and of a ntich higher specific gravity than in 

 health, usually about 1-040. Occjsionally, there is no separation into 

 coagulum and serum, the whole kiass of the blood remaining thick 





like 



