Chemistry : general, medical, and pharmaceutical including the chemistry of the ; a manual on the general principles of the science, and their applications in medicine and pharmacy . 84. a metre long, and having a slightly narrowed mouth, the tubebeing held in a cloth to protect the hand while the hot oxideis being directly introduced into the mouth of the tube by ascooping motion. As soon as the well-corked tube is cool, theoxide is poured, portion by portion, into a similar tube (thecombustion-tube), but somewhat longer, drawn out to a quill(bent upwards nearly to a right an
Chemistry : general, medical, and pharmaceutical including the chemistry of the ; a manual on the general principles of the science, and their applications in medicine and pharmacy . 84. a metre long, and having a slightly narrowed mouth, the tubebeing held in a cloth to protect the hand while the hot oxideis being directly introduced into the mouth of the tube by ascooping motion. As soon as the well-corked tube is cool, theoxide is poured, portion by portion, into a similar tube (thecombustion-tube), but somewhat longer, drawn out to a quill(bent upwards nearly to a right angle) at one end, and not con-stricted at the mouth. Two such tubes are readily made bysoftening in the blowpipe-flame two or three centimetres of thecentral part of a tube about a metre long, and drawing thehalves of the tube apart as shown in the following engraving(Fig. 85). The tubes are separated by melting the glass in the 598 QUANTITATIVE ANALYSIS. middle of the quilled portion. A few decigrammes of fusedchlorate of potassium should first be dropped into the ten or fifteen centimetres of oxide have been poured in,about a decigramme of the substance to be analyzed is dropped. down the tube, then a few grammes of oxide, then anotherdecigramme of substance, then more oxide, until three or fourdecigrammes of the body under examination have been fifteen or twenty centimetres of alternate layers are nextthoroughly mixed by a long copper wire having a short helix ;more oxide is introduced, the wire cleansed by twisting thehelix about in the pure oxide, and a plug of dry asbestosfinally placed on the top of the oxide at about five centimetresfrom the mouth of the tube ; the tube is then securely corked andset aside. The substance operated on may be pure white sugar,powdered, and dried; the tube in which it is contained isweighed before and after the removal of a portion for combus-tion ; the loss is the quantity employed in the combustion furna
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Keywords: ., bookcentury1, bookdecade1870, booksubjectpharmaceuticalchemistry
