Glass broken

Place 18 g. (12 ml.) of fuming nitric acid, sp. gr. 1 5, and 30 g. (16-5 ml.) of concentrated sulphuric acid and a few fragments of broken glass in a 250 or 500 ml. round-bottomed flask. Add gradually, in small portions, 14 g. of p-nitrotoluene do not allow the temperature to rise above 50 and cool the flask, if necessary, by immersion in cold water. Place a small funnel in the mouth of the flask and heat on a water bath at 90-95° for 30 minutes. Allow to cool almost to the laboratory temperature and pour the reaction mixture slowly into about 500 ml. of ice water containing a few small pieces of ice. Filter the crude dinitrotoluene through a Buchner funnel at the pump, wash it thoroughly with cold water, and drain as completely as possible. RecrystalUse from the minimum volume of hot methyl alcohol (flask, reflux condenser, and water bath experimental details as in Section IV,12). The yield of pure 2 4-dinitrotoluene, m.p. 71°, is 12 -5 g. 

E. Ozone destroyer. Ozone is a powerful irritant. The maximum possible working concentration has been reported to be 0,15 to 1.0 part per million of air. It is necessary to destroy any excess ozone and to see that the exit tube from the above absorption assembly is connected to a good hood. It is safer to incorporate an ozone destroyer in the set-up. One such destroyer consists of two tall towers (30 in.) filled with broken glass moistened with 5% aqueous sodimn hydroxide and connected in series (Note 10). The room in which an ozonizer is used should be well ventilated. 

Artifacts introduced through sample preparation are common materials these may be bits of facial tissue, wax, epithelial cells, hair, or dried stain, all inadvertently introduced by the microscopist. Detergent residues on so-called precleaned microscope slides and broken glass are common artifacts, as are knife marks and chatter marks from sectioning with a faulty blade, or scratch marks from grinding and polishing. 

Rubber or plastic gloves, face shields or goggles, rubber boots or over-shoes, face masks and an all-purpose respirator Household dustpan (rubber or polythene), brush and large bucket (preferably polythene), an ordinary steel shovel, stiff bristle brush and a soft brush, for sweeping up and containing broken glass, and industrial cotton mops, plastic foam mops or squeegees... 

Use forceps or a brush and pan with broken glass never use the fingers, even with gloves. Disinfect broken glass arising from biological spills... 

You should always anticipate hazards such as sharp objects like nails, broken glass, and medical needles slippery surfaces steep grades and potentially unstable surfaces such as walls, floors, or roofs that could cause falls, give way, or collapse. Other common physical hazards include ... 

True. The edges of broken glass can be razor sharp and cause serious injuries. Broken glass should never be left where other people can come into contact with it. 

X An alternative technique is as follows. Plunge the hot tube into about 10 ml. of water contained in a small, clean mortar and cover the latter immediately with a dean wire gauze. When the reaction is over, grind the mixture of solution and broken glass to ensure thorough extraction of the sodium salts. Transfer with the aid of a little water to a porcelt basin, heat to boiling, and filter. 

Dispose of broken glass, unused chemicals, and products of reactions only as directed by your teacher. 

Use of tools or glassware that can easily puncture or slice skin razor blades, pins, scalpels, pointed tools, dissecting probes, broken glass Practice common-sense behavior and follow guidelines for use of the tool. Go to your teacher for first aid. 

He shifts the painting under one arm and reaches to turn the frame down on its face on top of the broken glass. Oh, don t worry. I ll deal with it later. He holds out the painting. Here. I couldn t find anything else to carry down, but this you must have. I could never have sold it. I think you ve got its pair. ... 

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