Journal . rotected may be placed for any length of time over a powerful Argand burner, with-out giving the slightest sign of catching fire, pro-vided, of course, that the flame does not come in contact with any unprotected wood. After a cou- 20G THE JOURNAL OF THE SOCIETY OF CHEMICAL INDUSTRY. [March 29, iss- siderable time the wood is slowly ami completelycharred, the protectii - remaining intact. The great power of the draught thus produced has rendered it possible to dispense with draught cnP_ boards almost entirely. The draught arrangements on the working tables are extremely simple, and m
Journal . rotected may be placed for any length of time over a powerful Argand burner, with-out giving the slightest sign of catching fire, pro-vided, of course, that the flame does not come in contact with any unprotected wood. After a cou- 20G THE JOURNAL OF THE SOCIETY OF CHEMICAL INDUSTRY. [March 29, iss- siderable time the wood is slowly ami completelycharred, the protectii - remaining intact. The great power of the draught thus produced has rendered it possible to dispense with draught cnP_ boards almost entirely. The draught arrangements on the working tables are extremely simple, and may .lily understood by reference to Fig. 3. The wlmle of the fumes are drawn up the shaft. It willbe Been that the tables are further provided withglass hoods, c, r, Fig. 3. The object of these, hoods istwofold. i>n the one hand they act as screens, pre-venting the fall of dust, and more especially ofparticles of lime or plaster from the roof, on to thetables and into the open vessels of the workers. On. draught shaft*, a, lead down through the ceiling ofthe laboratory and terminate at the top of the tables,at each working place. In each shaft there is anopening, 6,6, Fig. 3, facing the worker, at a convenientheight, and provided with a sliding shutter. If theworker wishes to perform any operation in whichfumes are given off, he simply opens the shutter andhis apparatus opposite the opening, when the the other hand they collect and localise any fumeswhich are either accidentally or unavoidably producedat the several working tables. At the points (/, d,Fig. 3, immediately below the top of the hood, thereare two openings in each shaft, through which anyfumes that may collect at the top of the hood aredrawn away. (>f course, if the air were allowed fulland constant access to these upper openings, the March29,1887.] THE JOURNAL OF THE SOCIETY OF CHEMICAL INDUSTRY. 207 lower draught tubes would be little or no use, as thedraught through them would lie almost entirely cutoff. T
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectchemist, bookyear1882
