A Compendious Manual of Qualitative Chemical AnalysisFor the authors, 1868 - 139 pàgines |
Altres edicions - Mostra-ho tot
A Compendious Manual of Qualitative Chemical Analysis Charles William Eliot,Frank Humphreys Storer Visualització completa - 1869 |
A Compendious Manual of Qualitative Chemical Analysis Charles William Eliot,Frank Humphreys Storer Visualització completa - 1877 |
A Compendious Manual of Qualitative Chemical Analysis Charles William Eliot,Frank Humphreys Storer Visualització completa - 1872 |
Frases i termes més freqüents
acetic acid acid solution alkaline ammonia ammonia-water ammonium ammonium-salts antimony aqueous solution arsenic arsenic acid barium beaker bismuth boiling bottle bromides calcium caoutchouc carbonate of ammonium carbonate of sodium caustic soda charcoal chlorates chloride of ammonium chromate chromium classes of salts cobalt compounds copper cork crucible cyanide dilute chlorhydric acid dissolve drop dryness evaporated filter filtrate flask fluoride funnel glass tube globule hydrate hyposulphite ignited insoluble in water iodide iron lamp lead liquid magnesium manganese members of Class mercury metallic elements mixed mortar neutral nitrate nitrate of silver nitric acid non-metallic original solution oxalates oxide paper phosphate platinum platinum crucible platinum foil porcelain porcelain dish potassium powder precipitate presence produced qualitative analysis quantity reaction reagent residue separate silicic acid sodium soluble solvent stoppers strontium substance sulphate sulphide sulphuretted hydrogen sulphuric acid tartaric acid test-tube thrown tion wash wire yellow color zinc
Passatges populars
Pàgina 15 - By the screw dy the brass tube f is attached to the casting a b. The diameter of the face e, and therefore the internal diameter of the tube /, -should be 8 mm The length of the tube /is 9 cm Through the wall of this tube, four holes 5 mm in diameter are to be cut at such a height that the bottom of each hole will come 1 mm above the face e when the tube is screwed upon a b. These holes are of course opposite each other in pairs. The finished lamp is also shown in Fig. VII. To the tube ba caoutchouc...
Pàgina 29 - If it is desirable that the finer tube should have thicker walls in proportion to its bore than the original tube, it is only necessary to keep the heated portion soft for two or three minutes before drawing out the tube, pressing the parts slightly together the while. By this process the glass will be thickened at the hot ring. To obtain a tube closed at one end, it is best to take a piece of tubing, open at both ends, and long enough to make two closed tubes. In the middle of the tube a ring of...
Pàgina 27 - ... sometimes bear the most sudden changes of temperature, but thick glass and glass of uneven thickness absolutely require slow heating and annealing. When the end of a tube is to be heated, as in rounding sharp edges, more care is required in consequence of the great facility with which cracks start at an edge. A tube should, therefore, always be brought first into the current of hot air beyond the actual flame of the gas- or spirit-lamp, and there thoroughly warmed, before it is introduced into...
Pàgina 29 - The knob being hotter, and therefore softer than any other part, yields to the pressure from within, spreads out and disappears. If the knob is large, it may be drawn off by sticking to it a fragment of tube, and then softening the glass above the junction. The same process may be applied to the too pointed end of the righthand half of the original tube, or to any misshapen result of an unsuccessful attempt to close a tube, or to any bit of tube which is too short to make two closed tubes. When the...
Pàgina 26 - Whenever the place of experiment is supplied with common illuminating gas, a very small jet of burning gas may be advantageously substituted for the hot coal or slow match. To obtain such a sharp jet, a piece of hard glass tube, No. 5, 10 cm long, and drawn to a very fine point...
Pàgina 32 - The kinds sold as champagne corks and as satin corks for phials are suitable for chemical use. The best corks generally need to be softened before using ; this softening may be effected by rolling the cork under a board upon the table, or under the foot upon the clean floor, or by gently squeezing it on all sides with the well-known tool expressly adapted for this purpose, and thence called a cork-squeezer. Steaming also softens the hardest corks. Corks must often be cut with cleanness and precision...
Pàgina 31 - Caoutchouc. — Vulcanized caoutchouc is a most useful substance in the laboratory, on account of its elasticity and because it resists so well most of the corrosive substances with which the chemist deals. It is used in three...
Pàgina 37 - Agate mortars are only intended for trituration ; a blow would break them. They are exceedingly hard, and impermeable. The material is so precious and so hard to work, that agate mortars are always small. The pestles are generally inconveniently short, — a difficulty which may be remedied by fitting the agate pestle into a wooden handle. In all grinding operations in mortars, whether of porcelain or agate, it is expedient to put only a small quantity of the substance to be powdered into the mortar...
Pàgina 12 - Via. xxiv. and one thickness upon the other, as shown in the upper half of Fig. XXIV ; the filter is then placed in a glass funnel, the angle of which should be precisely that of the' opened paper, viz., 60°. The paper may be so folded as to fit a funnel whose angle is more or less than 60°, but this is the most advantageous angle, and funnels should be selected with reference to their correctness in this respect. In the second method of folding filters, the circle of paper is doubled once upon...
Pàgina 30 - By watching the expanding glass, the proper moment -for arresting the pressure may usually be determined. If the bulb obtained be not large enough, it may be reheated and enlarged by blowing into it again, provided that a sufficient thickness of glass remain. It is sometimes necessary to make a hole in the side of a tube or other thin glass apparatus. This may be done by directing a pointed flame from the blast-lamp upon the place where the hole is to be, until a small spot is red-hot, and then blowing...