'BRISTOL' GREEN WINE GLASSES
Having recently taken a brief look at the derivation of Bristol blue glass, it seems like an unusually consequent step to now give some thought to its cousin, so called Bristol green glass. The provenance of this outwardly similar product is, however, nothing like as clear cut…
Green glass was a ubiquitous term used in the 17th and 18th centuries to refer to a very utilitarian material which was often used to produce bottles, flasks and low-grade window glass. It was, essentially, clear glass which turned out unintentionally dirty having been contaminated the inclusion of impurities in its raw materials – and it could just as easily turn out a murky brown as it could green. That’s not to say that green-tinted glass had never been made deliberately – you only have to consider traditional roemers from the Low Countries and Germany to see that when the elements which caused the unwanted discolouration were identified and their inclusion in the production process controlled, the resulting pale green colour suddenly became quite desirable!
During the 18th century, the same process by which this inadvertent colouration was applied was also deliberately contrived in the production of glass – again predominantly in Germany – which was then used for the production of vessels destined for the apothecary’s workshop or chemist’s laboratory. A French alchemist by the name of Mssr Fontanieu – no doubt familiar with the science behind the process – worked tirelessly to achieve a deeper and more aesthetic effect and achieved success to some degree by producing what he referred to as ‘artifical emerald’ by using distillates of copper oxide or ‘crystals of verdigris’. Fontanieu’s results were striking but proved to be inordinately time consuming to replicate and prohibitively expensive, so he was unable to employ his methods to any sort of commercially viable end.
You will recall that one of the pioneers of Bristol blue glass, William Cooksworthy, was also well versed in the ways of chemistry, and it would appear that he had also attempted to formulate a proper green glass using chromium oxides, but time was to overtake him, and he had not achieved any published successes with his endeavours – nor left any experimental samples – prior to his death in 1780. However, it seems that the seeds of green glass production had been sown by Cooksworthy’s research, and by the end of the 18th century it is documented that a ‘fine, deep green bottle glass’ had been produced in the workshops of the Bristolian John Lucas, based at Nailsea in Gloucestershire. This production coincides with a period during which crocoite ore, a source of chromium oxide mined in Russia’s Ural Mountains, was starting to appear in the UK, having followed the same route into the country, via Bristol, as had Cooksworthy’s blue smalt derivative some years earlier. I can only assume that it was this point of entry for the mineral which engendered its common name as used in glass production, as had been the case with its blue antecedent.