How to Fire-Polish the End of a Glass Tube

Chipped and broken ends of tubes are common sights in the average laboratory. Because it is easy to repair this dangerous and unnecessary situation, there is no reason not to take a torch in hand and repair the problem. However, there are a few limitations involved  

If there are crack lines radiating from a broken section (see Fig. 8.11), 

A simple chip on the edge of a glass tube is simple to fire-polish. 

The glass on the base of a graduated cylinder or on the rim of a funnel is very thick and very difficult to fire-polish. If it is 

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