Strontii Lactas. U. S. ODOR, TASTE, AND SOLUBILITY. A white, granular powder, or crystalline nodules, permanent in the air. The solution, saturated at a boiling heat, remains liquid for many hours, even after being cooled to 0° C. (32° F.). When heated to 110° C. (230° F.), the salt loses its water (16.9 per cent.). At a higher temperature it first fuses, then is decomposed, giving off inflammable vapors, and leaves a residue of strontium carbonate and carbon, which, on the addition of hydrochloric acid, effervesces and communicates an intensely red color to a nonluminous flame. Odorless; slightly lution slowly forms a white pre-Carbonate, Oxalate, cipitate of strontium sulphate, insoluble in diluted acids. The same reaction occurs more quickly with diluted sulphuric acid, potassium sulphate T.S., or other solu etc. ble sulphates. With potassium Arsenic, Lead, etc. chromate T.S. it forms a yellow precipitate of strontium chro etc. Limit of Chloride, etc. mate, soluble in acetic acid. With Iron, Aluminum, ammonium carbonate T.S., or sodium carbonate T.S., it forms a white precipitate of strontium Barium. carbonate, soluble, with effervescence, in acetic acid. If to 5 C.c. of the solution (1 in 20) 1 C.c. of sulphuric acid be added, and then 1 C.c. of decinormal potassium permanganate V.S., the red color will rapidly disappear, while the mixture will effervesce and give Carbonate, Oxalate, off the odor of aldehyde. If 1.33 Gm. of the salt, previously rendered anhydrous by careful drying at 110° C. (230° F.), be ignited, until most of the carbon has disappeared, and then distributed in 10 C.c. of water, it should require, for complete neutralization, not less than 9.9 C.c. of normal sulphuric acid (corresponding to at least 98.6 per cent. of the pure salt), methyl-orange being used as indicator. etc. Butyrate, Propionate, etc. Limit of Readily Carbonizable Organic Impurities. TESTS FOR IMPURITIES. If 1 Gm. of the salt be dissolved in 19 C.c. of water, it should form a perfectly clear, colorless solution, leaving no insoluble residue. The aqueous solution should not be affected by hydrogen sulphide T.S., either before or after acidulation with a drop of hydrochloric acid, Nor by ammonium sulphide T.S. No turbidity should be produced in the solution by potassium dichromate T.S. If 0.5 C.c. of silver nitrate T.S. be added to 5 C.c. of the aqueous solution, not more than a slight opalescence should be perceptible. If 0.5 Gm. of the salt be placed upon a watch-glass, and 1 C.c. of sulphuric acid be carefully poured upon it, no effervescence should occur, Nor should any penetrating odor be perceptible, even after gentle heating, Nor should the acid assume, within ten minutes, a deeper color than a pale straw-yellow. Uses. This salt is recommended in the treatment of nephritis, rheumatism, gout, etc., in doses of ten to thirty grains (0.6 to 1.9 Gm.). QUESTIONS ON CHAPTER XLII. MAGNESIUM, CALCIUM, BARIUM, STRONTIUM. Magnesium-Give formula in symbols and molecular weight. What are the tests for the salts of magnesium? Magnesia-Give formula in symbols and molecular weight. How is it prepared? Describe rationale of process. What change takes place on exposure to air and moisture? Describe odor, taste, chemical reaction, and solubility. Give tests for identity. How may the following impurities be detected ?-viz.: Carbonate; more than traces of other alkaline earths; sulphates; chloride. What is the dose? Magnesia ponderosa-Wherein does this differ from magnesia? Magnesium carbonate-Give formula in symbols and molecular weight. What is the process of the British Pharmacopoeia for making this? Describe rationale of process. How may light magnesium carbonate be prepared? Describe odor, taste, chemical reaction, and solubility. Give tests for identity. How may the following impurities be detected?-viz.: Aluminum, or more than traces of calcium; metals; limit of sulphate; chloride. What is the dose? Effervescent magnesium citrate-Give Latin official name. How is it prepared, and what is the object of this preparation? If exposed to the air, what change takes place? Describe odor, taste, chemical reaction, and solubility. Give tests for identity. How may impurity of tartrate be detected? What is the dose? Magnesium sulphate-Give formula in symbols and molecular weight. How is it sometimes prepared in England? How much water of crystallization does it contain? Describe odor, taste, chemical reaction, and solubility. Give tests for identity. How may the following impurities be detected ?—viz.: Metals; alkaline earths; chloride; more than about 1 per cent. of sulphate of alkalies. What is the dose? Solution of magnesium citrate-Give Latin official name. What modifications of the official process are advisable? What is the dose? How much magnesia does each troche of magnesia contain? In what forms does calcium occur? What are its physical properties? What are the tests for salts of calcium? Lime-Give formula in symbols and molecular weight. How is it obtained? Describe odor, taste, chemical reaction, and solubility. Give tests for identity. How may the following impurities be detected?-viz.: Carbonate; insoluble matter. What is the dose? Lime water-Give Latin official name. How is it made? How much calcium hydrate does it contain? Give formula in symbols and molecular weight of calcium hydrate. Is lime more soluble in hot or in cold water? Describe odor, taste, chemical reaction, and solubility. Give tests for identity. How may impurities of alkalies or their carbonates be detected? What is the dose? How is syrup of lime made? What is the object of making a syrup of lime? What is lime liniment? What is a popular name for it? For what purpose is it used? Chlorinated lime-Give Latin official name. Upon what does the activity of this compound depend? What is sulphurated lime? How is it made? How much calcium sulphide should it contain? How may this be tested? In what two ways may this preparation be made? Explain the reaction which takes place between milk of lime and solution of ammonium bromide when mixed. Describe odor, taste, chemical reaction, and solubility. Give tests for identity. How may the following impurities be detected?-viz.: Bromate; iodide; sulphate; chloride; magnesium. What is the dose? Precipitated calcium carbonate-Give the British official process for making it. How may the fineness of the pwder be promoted? In what process is this salt obtained as a by-product? Describe odor, taste, chemical reaction, and solubility. Give tests for identity. How may the following impurities be detected?-viz.: Magnesium; aluminum, iron, or phosphate. What is the dose? Which is preferred for chalk mixtures-this, or prepared chalk, and why? What is the process for making it (formerly official)? What is the object of this process? Describe odor, taste, chemical reaction, and solubility. Give tests for identity. How may the following impurities be detected?-viz.: Barium or strontium; magnesium; iron. For what is it used, and into what official preparation does it enter? What is whiting, and for what is it used? Calcium chloride-Give formula in symbols and molecular weight. How may this salt be prepared? Describe odor, taste, chemical reaction, and solubility. Give tests for identity. How may the following impurities be detected?-viz.: Aluminum or iron; sulphate; magnesium. For what purpose is it used? Calcium hypophosphite-Give Latin name, formula in symbols, and molecular weight. How is this salt prepared? Describe rationale of process. What temperature should be employed in evaporating the solution? Describe odor, taste, chemical reaction, and solubility. Give tests for identity. How may the following impurities be detected ?—viz.: Insoluble calcium salts; soluble phosphate; soluble sulphate; magnesium. What is the dose? How is syrup of hypophosphites made? What is the object of using citric acid? How is syrup of hypophosphites with iron made? Precipitated calcium phosphate-Give Latin name, formula in symbols, and molecular weight. How is it prepared? Describe odor, taste, chemical reaction, and solubility. Give tests for identity. How may the following impurities be detected ?-viz.: Carbonate; aluminum. What is the dose? Give the Latin name of dried calcium sulphate. What is its common name or synonyme? How is it prepared? What is its composition? Syrup of calcium lactophosphate-Give Latin official name. How is it made? What is the dose? Compound chalk powder-Give Latin official name. How is it made? For what is it used? How is chalk mixture made? What is the composition of troches of chalk? Barium-Give symbol and atomic weight. What salts of barium are used officially, and for what? How is it found in nature? What are the tests for salts of barium? Strontium-Give symbol and atomic weight. What salts of strontium are used officially, and for what? CHAPTER XLIII. ZINC, ALUMINUM, CERIUM, AND CADMIUM. Zn; 65.1. Al; 27.04. Ce; 139.9. Cd; 111.5. THESE metals are grouped together on account of the similarity in some of their physical properties, rather than because of the chemical analogies existing between them. ZINCUM. U.S. Zinc. Zn; 65.10. Metallic Zinc, in the form of thin sheets, or irregular, granulated pieces. Preparation.-Zine is made by roasting calamine, or the impure zinc carbonate, with charcoal, in powder, and collecting the zinc by distillation, the vapors being conducted into water, where the zinc is condensed. It is bivalent, and combines with oxygen, chlorine, and phosphorus, forming zinc oxide, chloride, and phosphide, and with numerous acids to form salts. Tests for Zinc Salts. 1. Ammonium sulphide, if added to a solution of a zinc salt containing an excess of alkaline hydrate, produces a characteristic white precipitate of zinc sulphide. 2. The alkaline hydrates of either sodium, potassium, or ammonium produce white precipitates of zinc hydrate, freely soluble in an excess of alkali. 3. Sodium and potassium carbonates yield white precipitates, insolubie in an excess. 4. The zinc salts are all colorless. Zincum. U. S. A bluish-white metal, showing a crystal- The solution should be clear and color- Uses.-Zinc is used in making hydrogen and in preparing the zinc salts. Official Name. Zincum Zinci Acetas. Zinci Bromidum Zinc and Official Preparations. Preparations. Made by roasting the impure carbonate with charcoal and distilling. By treating zinc carbonate with acetic acid. By double decomposition of zinc sulphate and potassium bromide. Zinci Carbonas Præcipitatus. By double decomposition of zinc sulphate and sodium carbonate. By evaporating the solution of zinc chloride. By digesting zinc with iodine diffused in water. By incorporating zinc oxide with benzoinated lard. By passing vapors of phosphorus over fused zinc in a current of dry hydrogen. By acting on zinc with diluted sulphuric acid. By double decomposition of zinc sulphate and sodium valerianate. By sifting zinc oxide upon oleic acid and heating gently until dissolved. Unofficial Salts of Zinc. Zinci et Potassii Cyanidum. K2ZnCy. Zinci Ferrocyanidum, Zn4(C3N3)4Fe2. Zinci Lactas, Zn(C3H5O3)2.3 H20. Zinci Salicylas, Zn(C7H5O3)2.3H2O. Zinci Sulphocarbolas, Zn(C6H5SO4)2.8H2O. Zinc Sulphocarbolate. Zinci Tartras. Zinc Tartrate. By adding hydrocyanic acid to a solution of zinc acetate and collecting the precipitate. By dissolving zinc cyanide in a solution of pure potassium cyanide, filtering, concentrating, then crystallizing. By making a solution of zinc sulphate and one of potassium ferrocyanide, mixing them, and collecting the precipitate. Dissolving, by the aid of heat, zinc carbonate in diluted lactic acid, filtering and concentrating, then crystallizing. By heating salicylic acid with distilled water, gradually adding zinc oxide suspended in water, until no longer dissolved, filtering, and then crystallizing. By mixing concentrated solutions of barium sulphocarbolate and zinc carbonate and collecting the precipitate. By mixing hot concentrated solutions of zinc sulphate and neutral potassium tartrate, collecting the precipitate, and drying it. ZINCI ACETAS. U. S. Zinc Acetate. Zn(C,H,O,),+2H,O=218.74. Preparation. This salt may be made by the former official process: Take of Commercial Oxide of Zinc 2 oz. troy; Acetic Acid 83 f. oz.; Distilled Water 5 fl. oz. Mix the Acid and Water, and digest the Oxide of Zinc in the mixture for half an hour, then heat to the boiling point, filter while hot, and set aside to crystallize. Drain the crystals in a funnel, and dry them upon bibulous paper. An additional quantity of crystals may be obtained by evaporating the mother-liquor to one-half, slightly acidulating with acetic acid, and crystallizing. The reaction is expressed as follows: |