Mirrors and baubles
Yet Leibig’s most visible contribution to Christmas may well be hanging on your Christmas tree. Christmas trees have their roots as far back as the Roman saturnalian celebration of the winter solstices – a religious festival involving drinking, singing and exchange of gifts, dedicated to the Roman god Saturn. Later, probably sometime in the 16th century, decorated trees were brought into homes and this German idea was then popularised by Queen Victoria in the mid 19th Century.
Some of the first reported glass decorations for trees, dating back to the 16th century, were garlands of beads produced by the Greiner family in Lauscha, Germany. Some 250 years later, the family were still making ornaments, and Hans Greiner became famous for his ornate glass nuts and fruits, decorated with mirrored internal surfaces.
At the time, mirrors were prohibitively expense for most and were made by adhering a thin tin film to glass using mercury. The process was extremely hazardous as it generated highly toxic mercury vapour, which could also leach off the mirror for decades to come. In fact antique mercury mirrors may be identified by droplets of mercury pooling at their base.
At more or less the same time as Hans Greiner was creating his baubles, Liebig was developing much safer ways to silver glassware for use in his laboratories. His method utilised silver nitrate, ammonia and simple sugars. And it resulted in a fabulously uniform, crystal-clear film of silver metal deposited on the glass. This was soon adapted for use in other areas of science, including telescope mirrors, and soon Greiner caught wind of the development and incorporated it into his ornaments. Eventually the process also led to mass-produced mirrors which were cheap enough to make them commonplace.