The independent practitioner : a monthly journal, devoted to medicine, surgery, obstetrics, dentistry, pathology and popular science . being observed to prevent accidents. Whenthe volume had been reduced to about fifty c. c. the solution wasfiltered into a porcelain vessel, and still further reduced over thewater-bath. A portion of the solution tested in the short tube ofa Mitscherlich double-shadow polaristrobometer gave, as a mean ofv->s-readings, a rotation of the plane of polarization equal to0,015 degrees, or 0° 0,9. In other words, the solution was opti-cally inactive, the 0° 0,9 bein
The independent practitioner : a monthly journal, devoted to medicine, surgery, obstetrics, dentistry, pathology and popular science . being observed to prevent accidents. Whenthe volume had been reduced to about fifty c. c. the solution wasfiltered into a porcelain vessel, and still further reduced over thewater-bath. A portion of the solution tested in the short tube ofa Mitscherlich double-shadow polaristrobometer gave, as a mean ofv->s-readings, a rotation of the plane of polarization equal to0,015 degrees, or 0° 0,9. In other words, the solution was opti-cally inactive, the 0° 0,9 being far within the range of the errorof experiment, especially as the solution was not absolutely trans-parent. An excess of freshly prepared oxide of zinc was then added tothe solution, and the whole slowly and carefully boiled, water beingadded as it was found necessary, till the reaction became neutral,or nearly so, filtered into a large glass evaporating dish, and putaway at the temperature of the room for the salt to drop of this solution placed upon a glass slide gave, upon crys- 116 Original tallization, the forms seen in figure one, which are at once recog-pj j nized as crystals of lactate of zinc. In a few days a quantity of a whitish crys-talline powder had formed. This wasplaced upon a filter, the mother-liquidsqueezed out, washed in absolute alcohol,dissolved in hot water, re-crystallized anddried over sulphuric acid; it then weighed0,343. After exposing to a temperatureof one hundred degrees Centigrade, or alittle more, till the weight became con-stant, it weighed 0,2816; it lost accordingly 1*7,9 per cent.* of waterof crystallization, corresponding to three molecules of salt was then dissolved in water, the zinc precipitated as car-bonate and burned. The burned mass (zinc oxide) weighed 0,0970,We have consequently: Substance analyzed (a zinc salt) = 0,343Oxide of zinc = 0,097 The zinc oxide is seen to be equivalent to 28,2
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectdentist, bookyear1883
