Some Experiments on the Effects of Humidity on the Weathering of Bottle Glasses

JSGT 1939 V23 T242-T252

 The alkali extracted from the interior of three different brands of 4 oz. medicine bottles by boiling for five hours with water was determined very soon after the bottles had been made. Other bottles of each brand were then stored (some with interior as received, some after being washed) for a period exceeding eleven months, some at 25° in specially constructed chambers containing phosphorus pentoxide (and therefore of zero humidity), some in similar chambers at constant relative humidity of 76 per cent, and some, with mouths covered by muslin, in a room subject to normal variations of atmospheric temperature and humidity. Observations of appearance were made throughout the period. At the end the acidity or alkalinity of interior and exterior was determined, and the general durability of the interior re-determined after a preliminary washing. The durability of bottles stored at zero humidity remained practically unchanged and no film of crystalline products of weathering was produced. Bottles exposed to a humid atmosphere, either in an enclosed chamber or a room, developed crystalline films (more regular and finer when in the chamber) and the durability of the resulting surfaces was substantially improved as the outcome of such exposure.

Violet Dimbleby, M.Sc., F.S.G.T., and Professor W. E. S. Turner