OCR Text |
Show subside; decant the clear solution, and qvaporpts it to nine pounds. To this liquor, poured from the impurities, addcar- bonate of soda, dissolved in warm water, until the effervescence cease. Filter the neutralized liquor, and set it aside to crystal. lize. To the liquor that remains after the crystals are taken out, add a little carbonate of soda, if necessary, he as to satu. rate exactly the phosphoric acid ; and dispose 4 liquor, by iad poration, to form crystals. Lastly, the crystals are to be kept in a well closed vessel. Dub. Take of burnt bones, in powder, five pounds ; — sulphuric acid, three pounds and a half, by weight: Mix the pow der, in an earthen vessel, with the slphuric ae gradually add five pints of water, and agitate the mixture; digest for three days, adding, from time to time, more Water, t9 o vent the mass from becoming dry, and continuing the agitation : then addfive pints of boiling water, and strain through ee pouring on boiling water repeatedly, until all the acid pe washed out. Set aside the strainedliquor until the feces subside, from which pour it off, and reduce, by evaporation, to one half; ve add of carbonate of soda, dissolved in a sufficient quantity of warm water, three pounds ten ounces. Filter, and, by ae poration and cooling, let it form crystals, whichare to be key eae in a well-closed vessel. If the salt be not sufficiently pure, dissolve and crystallize it again. "oP he first part of this process consists in destroying the a tine of the bones by the action of heat. When burnt to per : whiteness, they retain their form, but become friable, and ony sist of phosphate of lime, mixed with a very litte ae lime And carbonate of soda. In performing this part of the process, we must take care not to heat the bones to a bright red, as j : semi-fusi ‘and becon »come Jess saluby iit they undergo a kind of semi-fusion, ble. PRICKLY PRICKLY SALTWORT, 272 by i ‘coal is is facili facilitate d i of the charcoal The complete combustion the free contact of the air; we must therefore bring every| art, in succession, to the surface, and break the larger pieces. ee In the second part of the process the phosphate seth SALTWORT, with the rest of the phosphate of lime, and forms super-phos- phate of lime, which is not further decomposable by sulphuri c acid. The snper-phosphate of lime, thus formed, is soluble in water ; but, as the sulphate of lime, with which it is mixed, concrete s into a verysolid mass, it is, in some measure, defende d fromthe action of water. On this account the whole mass is directed to be digested for three days in vapour, by which means it is thoroughly penetrated, and prepared for solution, in the boiling water, which is afterwards poured on it. It is probabl y to render the subsequent solution easier, that Thenarddirects the bone-ashes to be made into a thin paste (louillie) with water before the sulphuric acid is added to them. Having thus got a solution of super-phosphate of lime, it is next decomposed by carbonate of sodadissolved in water. This decomposition, likewise, is onlypartial, as it deprives the super- phosphate of lime of its excess of acid only, and reduces it to the state of phosphate. The phosphate of lime, being insolubl e, is easily separated byfiltration, and the phosphate of soda reinains in solution. Mr. Funcke, of Linz, has discovereda still more ceconomical and expeditious method. It consists in saturating the excess of lime in calcined bones with diluted sulphuric acid, and then dis- solving the remaining phosphate oflime in nitric acid. T'o this solution he adds an equal quantity of sulphate of soda, and then Tecovers the nitric acid bydistillation. The phosphate of soda is then separated from the sulphate of lime by the affusion of water and crystallization. Phosphate of soda crystallizes in rhomboidal prisms, termis nated by three-sided pyramids. Its taste resembles that of common salt. At 60° it is soluble in four parts of water, and at 212° in two. It effloresces in the air. By heatit undergo es the Watery fusion, and at last melts into a white mass. It consists, according to Thenard, of 15 phosphoric acid, 19 soda, and 66 Water of crystallization. having an earthybase. f It is decomposed by most of the salts MEDICAL USE. This lenOR 4 : Phosphate af soda was introduced into the practice of physic ever, only partial. ‘The sulphuric acid combines mi . : the lime, and forms insoluble sulphate of lime. 5 he ee acid separated from that portion of lime, immediately combine the same medical qualities as sulphate of soda, and the tartrate of potash and soda, being an excellent purgative, in the quantity decomposed bythe sulphuric acid. »y the ingenious Dr. G eorge Pearson of London. tp It possesses |