Chemistry labs are places where you can find dozens of different types of glassware. Nowadays a lot of it has been replaced by plastic, but the old names are retained. You can have plastic beakers, plastic test tubes, plastic Florence flasks, plastic watch glasses. Of course you still need glass if there is a need to apply a flame to heat up some brew. Then there are the particular pieces of glassware that have rather interesting names like a Liebig Condenser, a Markham Still, a Nestler Tube, a Conway Dish and a Dewar Flask. The latter is, or was, quite common in the world outside the laboratory, only there it was usually known as a Thermos Flask. The original device was designed by a gentleman named Dewar funnily enough, and this is the usual name applied in laboratories. It comprises of a hollow walled glass vessel with the insides of the wall coated with silver and all the air pumped out of this cavity. This greatly reduces the passage of heat through the walls, so any material contained stays hot or cold for long periods, but you know that, don’t you?
Periodically, a clerical type bloke used to turn up at our lab to run an audit on our equipment. Now glass has a tendency to fracture and even the most careful technician has had a flask, beaker, tube or bottle disintegrate and screw up a morning’s work. The causes are manifold. Explosions, implosions, thermal and gravitational. The beauty of plastic is that it bounces and bends better. So glassware is not usually listed on the lab manifest. However there may be some exceptions due to the capital cost of the piece. If such a valuable item becomes unusable than it has to be kept until it is removed from the manifest by the appropriate official, i.e. the auditor. So you store the useless thing. Them’s the rules.
One memorable day, the auditor arrived and we commenced to go through the inventory, checking off the entries. The work proceeded smoothly until we came upon an item we had difficulty locating. It was one of those small but expensive bits of glassware that had unfortunately cracked in use and so become unusable. It had happened months before and we knew we had shoved it in the back of some cupboard, but none of us could recall which one. So the hunt began. Beakers and flasks were hauled out of cupboard after cupboard and placed on the bench top. From the deepest recess of one cupboard emerged one very interesting item, a whiskey bottle. We all knew it was a whiskey bottle. It was a very famous type of whiskey bottle due to its very distinctive shape. The auditor raised an eyebrow, the right one. “And what do you call that piece of apparatus?” he enquired. Without any hesitation and with a totally straight face the boss said “A Dewar Flask”. This was followed by a lot of groans and giggles. I don’t think that item got entered into the manifest, mainly because it was empty. Had it been full, it may have been another matter, and I wonder if it would have been as a Bell Flask or a Dimple Flask.
F Brown ©
