‘There are few sensations more pleasant than that of wondering,’ the philologist Max Müller declared at the opening of his Rede lecture, delivered in the University of Cambridge on 29 May 1868. The cause of wonder for Müller on this occasion was the thousands of years that humans had lived in ‘conscious ignorance’ of the ancient layers of rock and the remains of organic creatures, before geological eyes were opened in the eighteenth century; and, more strikingly, the centuries during which names had been given to a panoply of living things while ‘what was much nearer to them than even the gravel on which they trod, namely the words of their own language’, escaped systematic notice. ‘Here, too,’ Müller observed, ‘the clearly marked lines of different strata seemed almost to challenge attention, and the pulses of former life were still throbbing in the petrified forms imbedded in grammars and dictionaries’. Yet this attention did not fully arrive until the nineteenth century, when the idea that language was a fixed and stable structure gave way to the view that it was a ‘growing and developing medium’ (Hans Aarsleff), a material accumulation susceptible to sifting, analysing, and accounting. This paper will wonder about what new varieties of thought were made possible by the association of these fields, and the analogies they engendered. The vastness and composite complexity of the linguistic record, with models of preservation and decay borrowed from geology, prompted reappraisals both of the utility and applicability of universal laws to human culture, and a fundamental rethinking of language itself.