Essentials of chemistry : inorganic and organic, for the use of students in medicine / by R.A. Witthaus.

  • Rudolph August Witthaus
Date:
1879, ©1878
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Licence: Public Domain Mark

Credit: Essentials of chemistry : inorganic and organic, for the use of students in medicine / by R.A. Witthaus. Source: Wellcome Collection.

Provider: This material has been provided by the Harvey Cushing/John Hay Whitney Medical Library at Yale University, through the Medical Heritage Library. The original may be consulted at the Harvey Cushing/John Hay Whitney Medical Library at Yale University.

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    II. The compound is insoluble in icater, but is soluble in HCl, NO$H, or aqua regia. The method is the same with the acid solution (diluted) as in I. up to 11. Before proceeding to 12, it must be determined whether the substance be not a phosphate or oxalate of cal- cium, barium or strontium, or a fluoride, thus : 1. Treat a portion of the ppt. obtained in I. 11 with S04Ho in a platinum crucible, covered with a glass plate, a portion of whose lower surface is covered with wax ; warm the crucible slightly (not enough to melt the wax): a. Th e uncoated surface of glass is corroded ... Fluoride. b. It is not affected 2 [If the substance be a fluoride, add to the residue in the cru- cible excess of -sol. C03K2, boil a few moments, filter, wash the residue thoroughly, add dilute HC1. collect this filtrate, and proceed from 1.18 to discover the base.] 2. Add a little tartaric acid and excess (NH4)HO to origi- nal acid solution : a. A ppt. is formed 4 b. No ppt. is formed 3 3. To original acid sol. add excess sol. KHO until it is clear ; divide into three parts. To one add excess sol. (NH4)C1, to another recently prepared sol. chromic hydrate in sol. KHO : a. Ppt. with (NH4)C1 ; none with Cr sol Aluminium, b. No ppt. with (NH4)C1; green ppt. with Cr sol... .Zinc. To third portion add sol. S04Mg, and agitate ; if a white, crystalline ppt. be formed, the Zn or Al was a Phosphate. 4. Add to original acid sol. excess sodic acetate and sol. CaCl2 ; then acetic acid : a. A ppt. is formed which persists after addition of acetic acid Oxalate. b. No ppt. is formed, or it disappears on addition of acetic acid Phosphate. [If the substance be an oxalate, heat a portion of the original 6olid to redness, dissolve the cooled residue in dil. HC1. and proceed with I. 18 ; if it be a phosphate, add excess sol. Fe2Cl8 to original acid sol., then (NH4)HO, filter, and with filtrate pro- ceed with 1.18.]