renewed interest some ten years later: in 1811 Cuvier visited Haarlem on a tour through the
Netherlands £ he was on an assignment from the French government to assess the Low
Countries’ educational system - and spent some time at Teylers Museum studying the
collection; van Marum permitted him to analyse the homo diluvii testis and verify the
hypothesis that further excavation of the fossil would reveal the creature’s two leg-like paws -
a lighter colour still reveals where Cuvier chipped away at the stone surrounding the fossil.
And indeed, two small legs were laid bare, thereby making even more plausible that these
were the remains of some kind of salamander.
Other examples that reflect van Mamm’s interest in the issues surrounding fossil bones and
extinction from this period abound. On his journey to Germany in 1798 for instance he was
presented with one of the “Lying Stones” the unfortunate Professor Beringer had been coaxed
into believing were real fossils about seventy years earlier - having collected hundreds of
such “fossils” purportedly from a specific region over many years and even having published
scientific treatises on his “findings”, Beringer only realised he had become the victim of an
elaborate prank when he was presented with a fossil that had his own name written on it.
Van Mamm’s successor van Breda later purchased more of these Lying Stones. Another
example is provided by a letter van Marum sent to J.R. Coxe of the American Philosophical
Society in Philadelphia in 1802. He was writing in his function as secretary of the Holland
Society, but the letter is also a good example of how, on occasion, van Mamm was able to
capitalise on this to the benefit of Teylers Museum. Having exchanged periodicals with the
American Philosophical Society, van Mamm now added: “Comme je suis le directeur d’une
collection très étendue des minéraux et des pétrifications, et des parties animales fossiles » -
by which he of course meant Teylers — “qui est ce qui m’intéresse beaucoup d’acquérir
quelques ossements du mammouth, ou de l’animal qui se trouve près de l’Ohio.”94 The “Ohio
animal”, a mastodon then still thought to be a mammoth, had been found in the North
American region it was named after, and had been one of the most contested fossils before
Cuvier presented his theories.
But even though van Marum’s interest in the earth sciences evidently increased around the
turn of the century, it would be wrong to assume he was not interested in them before. The
opposite was in fact the case, as his early acquisition of the mosasaur and the publication of
his analysis thereof in 1790 already suggest. It is only that this area of research had been
eclipsed by electricity and chemistry before. It is equally important to recall that initially van
Marum had actually been appointed by the Foundation to take care of the growing fossil
collection and to keep it accessible to interested third parties - and that the trustees had only
reluctantly agreed to his establishing an instrument collection alongside the fossil collection.
Van Marum had, in fact, continued to purchase geological specimens such as minerals and
rocks throughout the 1780s.
93 See for example: Ibid., 8.
94 M. van Marum to J.R. Coxe, 18.04.1803, Philadelphia, APS, Archives, Record Group Ila.
15. A Matter of Faith
This brings us to the second main point that was mentioned above as important to keep in
mind when trying to understand the history and overall status of Teylers Museum’s geological
collection: that van Marum was a deeply religious person. More to the point, it was his
physico-theological approach to nature that shows more strongly in this area of collecting and
research than in any other. Time and time again he emphasised how he believed that a
systematic analysis of the earth and its properties would lead to a better understanding of
God’s work. What’s more, the idea was to pass on any insights gained in this way. During a
lecture on the earth sciences he gave before the trustees in 1798 van Marum himself
summarised what he saw as “the aim [...] for which this collection had been made at this
Foundation: namely, to give every philosophical observer the opportunity to enlarge his
insight into the works of the Creation.”95
Admittedly this remark was made within the context of a lecture on extinction, i.e. van
Mamm’s newest interest at the time, and other passages from the lecture clearly reflect the
impact Cuvier’s ideas had had on van Mamm’s view of the earth sciences ^ - IU^ ^ar more
crucially, van Mamm’s physico-theological approach to nature is already abundantly clear in
his inaugural lecture as town lecturer which he gave in 1777, and his strong belief had
certainly not waned by 1810 when he published his Catalogue des Plantes and quoted
Priestley saying “A life spent in the contemplation of the productions of Divine power,
wisdom, and goodness, would be a life of devotion”.96 One can safely assume that the
sentiments expressed in 1798 had indeed guided van Mamm all along, and also that they
continued to do so.
There can be no doubt that these sentiments would have resonated well with the tmstees, all
the more so because this chimed with the tenets set out by Pieter Teyler in his will. With this
in mind it is perhaps easier to understand why van Mamm was able to acquire items for the
geological collection even during the period in which no money was available for the
expansion of the instrument collection in the 1780s — although money was tight here too, and
van Mamm was initially told that he could not expand the geological collection any further.
It was only because van Mamm argued that it would look strange and possibly tarnish the
Foundation’s reputation if he suddenly ceased acquiring geological specimens at auctions
after hitherto having spent large amounts of money in the Foundation’s name, that the tmstees
provided him with the resources that had become available from the sale of some of Pieter
Teyler’s books.98 And even after that they don’t appear to have cut his budget for acquisitions
to zero, because a journal van Mamm kept of his acquisitions lists numerous and regular
95 “het oogmerk [...] waar toe deeze verzameling bij deeze Stichting is aangelegd: om namelijk, aan elken
wijsgeerigen beschouwer, geleegenheid te geeven zijne inzichten in de werken der Schepping uit te breiden
“Geologische Leszen bij Teylers Stichting 1798-1803”, 02.11.1798, Haarlem, NHA, Archief van Marum, vol.
529, nr. 6. , Tr .
96 Marum, Catalogue des plantes, cultivées au printems 1810; dans le Jardin de M. van Marum a Harlem, vin.
97 “Directienotulen”, 29.04.1785, Haarlem, ATS, vol. 5. (cf. footnote 25.)
98 Martinus van Marum: “Journal van mijne verrichtingen ter verkrijging eener verzameling van Fossilia m
Teyler’s Museum”, 1782-1790, Haarlem, NHA, vol. 529, Archief van Marum, nr. 1 ld, 15.04.1785.