Behind the scenes of the Teylers Museum
by Marijn van Hoorn
[paper composed from Martinus van Marum. Life & Work, vol. III, for the European Botanical and Horticulturtal Libraries Group, symposium Oslo May 2011]
Introduction / Preliminary notes
Before 1803: First garden
- Survey of correspondents
- Kew: Aiton and Banks
- Salm-Dyck (1813-1834, 273 letters)
- Reinwardt (1815-1837, 166 letters)
Biographical note 
Martinus van Marum is one of the most important scientists connected with the Teyler Foundation. He accomplished his studies at Groningen University in 1773 with a double Ph.D. on plant physiology. He would develop into a many-sided, productive physicist-chemist and natural history collector.
In 1776 he settled in Haarlem as a physician. But soon he became the pivot of the two scientific institutions in that city: the Teyler Foundation, and the Dutch Society of Sciences. Around 1800 he had become the central figure of the Dutch natural sciences. As Secretary of the Dutch Society of Sciences he corresponded with hundreds of European scientists.
At Teyler’s, he founded and headed, for more than half a century, the three natural sciences departments: the Cabinet of Physics, the Cabinet of Palaeontology and Mineralogy, and the Library of Natural History, which he made a library on botany in the first place. Besides, he had a large part in the activities of the Teyler Society, that promoted arts and sciences by means of prize questions.
For most of his life descriptive botany was his main interest. We will hear more about this soon. Everlasting fame he gained with his work on electrostatics and gas chemistry. He built the largest generator ever and published four volumes with experimental results. In the 1790’s he became, so to say, Lavoisier’s bulldog, as a defender and promoter of his new chemical theory based on the role of oxygen in combustion processes.
In the Napoleonic era Van Marum participated in the reform of higher education and contributed to the popularization of science and technology.
Introduction / Preliminary notes
In September 1819 the Danish professor of botany Hornemann wrote to Van Marum:
“Your [=Dutch] professors of botany are also professors of medecine, and that combination is almost always at the disadvantage of botany and gardening.”
He was right, and it is good to bear in mind that in the days we speak of now, botany was not yet an academic discipline in its own right. Also, in the days of Van Marum, botany meant description, taxonomy, classification; plant physiology was still in its infancy, Van Marum being one of its pioneers in the 1770’s. 
From the late 16th to the late 18th century Dutch gardens flourished with rich plant collections. This goes especially for the 17th century, the Dutch Golden Age. Economically, and culturally, the sky was the limit, and many of the well-to-do had a country-seat as well as a house in town. A garden was an essential part of such an estate, and in the course of time many of them became botanical gardens. A spin-off of the mercantile activities of our East and West India Companies were shipments of natural curiosities including plants and seeds, and many gardens contained these exotic treasuries.
Garden owners sometimes had their plants listed in a printed catalogue. This could be a simple inventory or a beautifully illustrated book. The most spectacular example is the Hartekamp, near Haarlem, a garden owned by George Clifford, a director of the Dutch East India Company. It was the Swede Carolus Linnaeus, who catalogued, described, and illustrated his plant collection, which led to the well-known publication Hortus Cliffortianus of 1738. 
Van Marum lived in the period of the big exploration travels, that started with James Cook in the 1770’s. These voyages were accompanied by scientists including botanists – think of Aimée Bonpland accompanying Alexander von Humboldt - , who made extensive collections of the exotic flora and fauna. For the most part, these discovery travels were undertaken by the English and the French. Many plants from those travels went to Kew and Paris, and were very hard to come by for plant collectors in other countries.
As already noticed, botany was Van Marum’s first love. It was only his bitter disappointment, that his Ph.D.’s of 1773 on plant physiology did not result in the -promised!- chair of botany at Groningen University, which made him turn to other fields of science. Still in Groningen, he started experimenting in electrostatics, built a new type of electrostatic generator, and published a book about it.
In 1776, at the age of 26, he settles in Haarlem. Within a couple of years he had assembled the important posts that he would occupy for the rest of his very long life:
- Director of the Natural Curiosities Cabinet of the Dutch Society of Sciences
- Secretary of the Dutch Society of Sciences
- Director of the Cabinets of Physics and Palaeontology/Mineralogy of Teyler’s Museum
- Director of Teyler’s Library (natural history, mainly botany)
Besides, what soon made Van Marum a man of independent means, was his marriage, in 1781, to Joanna Bosch, the only child of a wealthy printer who had died in 1780.
To the inheritance of his wife belonged a plot, on which Van Marum started his first garden in 1783. This garden was about the local Dutch flora and had few plants from abroad. In 1791 Van Marum was visited by Joseph Franz Jacquin  from Vienna; from their correspondence we know that at that time Van Marum already had plants from the Cape (of Good Hope). In 1794 started a correspondence with the Swede Carl Peter Thunberg  , at that time professor at Uppsala. Already in the 1770’s, as an employee of the Dutch East India Company, Thunberg had brought plants and seeds from the Cape to Holland. Van Marum asked for northern plants, suited for the Dutch climate.
The visit of André Thouin, French botanist and horticulturist, in 1795, was special in the sense that Thouin was a member of the French commission that was busy annexing Dutch collections for France. But all through the Revolutionary and Napoleonic years Van Marum was perfectly able to stay on friendly terms with French scientists, also with Thouin, who sent many seeds from Paris over the years.
In general, unfortunately, Van Marum’s first garden suffered from neglect as up to 1800 he was far too much occupied with all his other activities as a physicist, chemist, palaeontologist, and so on. Also, his travelling abroad took quite some time.
In the 1790’s there was exchange with the Hortus at Utrecht University. Van Marum had a very good relation with its young hortulanus, professor Steven Jan van Geuns . In co-operation they studied the Rainville herbarium:
Frederik Rainville was a botanist of French origin, who lived in Rotterdam, dying there in 1779. His collection of dried native and exotic grasses first went to professor Andreas Bonn at Amsterdam, on the condition that he would write a descriptive catalogue. In 1792 still nothing was done, and thereupon Rainville’s heir gave most of the collection to Van Marum, who decided, after consultation with Van Geuns, to study only the native grasses in Rainville’s huge herbarium. The results would be used to complete the Flora of the Netherlands by David de Gorter. Finally, this part of the collection would be placed in Teyler’s Library. This herbarium is still present ; it contains 175 sheets plus a detailed manuscript in Latin and Dutch by Van Marum. The rest of the material went to the Batavian Society for Experimental Philosophy at Rotterdam, and to the Royal Netherlands Academy of Sciences.
As Director of the Cabinet of Natural Curiosities Van Marum was supposed to expand the collection with zoological and botanical specimens. As far as botany is concerned, Van Marum was not lucky in his efforts, certainly not in his own perception, while the more objective observer has to conclude, that probably on more than one occasion he was asking too much! Contacts with Barthélemy Faujas de Saint Fond, professor of geology in Paris (1786), and professor Georg Franz Hoffmann, cryptogams specialist in Göttingen (1798-1801), were not very rewarding. In the case of Hoffmann, Van Marum only received a small portion of Hoffmann’s cryptogams collection. His attempt – in his quality of Secretary of the Dutch Society of Sciences – to seduce Hoffmann to send his complete collection by offering him a nomination for membership of the Society, failed. In 1802-1803 Van Marum wanted to sponsor two students of the Berlin professor C.L. Willdenow, for work in the Dutch East Indies. Clearly, he hoped to enrich his Cabinet with their shipments. But alas, this was not to be, due to illness of the one candidate, and when the other one wanted to depart, no vessel was available anymore. Nevertheless, exactly failures such as these serve to show us one of Van Marum’s most characteristic qualities: his tenacity.
1803: Plantlust 
Around the turn of the century Van Marum put an end to his researches in electrostatics and gas chemistry, for reasons we cannot deal with here. He returned, for good now, to his first interest, botany. In 1803 he bought a country-seat at the river Spaarne, naming it Plantlust. He enlarged it a bit in 1804, in order to be able to also cultivate foreign plants. Over the years he specialized in succulents.
In 1810 he had a catalogue printed to facilitate exchange . From this catalogue we learn that, at that time, he had 2.858 species in his garden, an amount that grew to more than 3.000 in 1814, and to 4.000 in 1818. This we know from his correspondence with W. Townsend Aiton and A.H. Haworth. Only in 1816 he had an orangery built, on the instigation of his correspondent Joseph prince of Salm-Dyck. The design was by his correspondent and friend Caspar Reinwardt. As you see, these are exactly his two main correspondents. In 1817 the garden equipment was completed with a hot-house for the tropical plants he was expecting from Dutch East India. It enabled him to cultivate succulents from leaves. From September 1823 onwards – Van Marum was 73 by then – he employed two gardeners.
In plants collecting, Van Marum strongly preferred to act on an exchange basis, although he also dealt with commercial nurseries. The numerous acquaintances he had made with European botanists during his travels, were most useful now. An extensive correspondence and exchange of plants and seeds resulted. In general, in his dealings for Plantlust and for colleague-botanists, Van Marum showed great perseverance and patience, necessary qualities for a discipline that was full of uncertainties in those days.
Survey list of correspondents 
England, Kew: Aiton and Banks
Botanical developments at the Royal Kew Gardens were very much shaped by Joseph Banks , a very influential man, for instance in his quality as President of the Royal Society. It was his idea to collect and grow plants from all over the world at Kew, and with his influence and money he also contributed heavily to its implementation. Thus Kew became the great exchange house of the British Empire, leading in testing the possibilities of acclimatising plants, and the source of material for experimental work in any climate. Kew Gardens possessed many rare species nowhere else to be had.
Unfortunately, Kew also was notorious for its ungenerosity as to requests for material. It was not only Van Marum, who, in 1814, came to nothing with Aiton: in his correspondence there are other examples, such as Otto, curator of the Schönberg Garten near Berlin, who, in 1816, complained that it was impossible to obtain succulents from England. From Chelsea, this was acknowledged by Haworth, who wrote, in 1821, that he did not think that the nurseryman J.C. Tate could [quote] “procure any succulents from Kew, at least not from Mr. Aiton or with his permission.” Th. Hitchen, a nurseryman from Norwich, writing in the same year, had the same strong opinion regarding Kew. And the prince of Salm-Dyck, in a letter of 1822 [quote]: “M. Aiton est un terrible homme pour la négligence qu’il met à tout.”
But was it really Aiton, who was to blame? No! We now know that it was Sir Joseph Banks in person who decided in these matters. He was very protective of the Kew collection, and his main consideration was that there should not be the slightest risk of losing a species! So, no wonder Van Marum, when he wrote directly to Banks after drawing a blank with Aiton, again got a negative reply: Banks’ answer was that at the time it was impossible to give plants to private persons, but in due time he would remember the ‘Jardin Teylerien’, (by which he meant Plantlust). And indeed, over the years on some occasions material from duplicate specimens was sent to Haarlem.
Salm-Dyck (1773-1861) 
Joseph M.F.A.H.I. zu Salm-Reifferscheid-Dyck, Prince of Salm, can be characterized botanically as one of the best experts on succulents in the nineteenth century. His estate with the garden, the Hortus Dyckensis , was situated between Aachen and Düsseldorf. His main work, Monographia generum Aloes et Mesembryanthemi , published between 1836 and 1863, was prepared in close co-operation with Van Marum. Their correspondence covers the years 1813-1834; from this period no less than 273 letters are extant.
The correspondence started after Salm came across a copy of Van Marum’s Plantlust catalogue of 1810 on a visit to the Brussels botanist Professor Adrien Dekin. For Van Marum and Salm the cultivation of succulents was a means towards their scientific description and naming. As botanist-gardeners, cultivating many plants side by side, observing them constantly, they were able to get well acquainted with the living plant, the basis for correct drawings and exact descriptions. All this as opposed to working with dried material only.
From the beginning Van Marum was supportive to the utmost regarding Salm’s intention of composing a monography of the genus Aloë [‘aelou]. He was involved in all problems and details connected with the editing of the monograph, concerning plates, size, language, data on cultivation, publication sequence, and so on.
In general, over the years, Salm’s collection always was given preference, and Van Marum’s activities for it were manifold:
As an intermediary, he bought plants from Dutch and English nurseries, obtained plants from Dutch university gardens, looked for rare species, ordered literature, copied texts and plates, and in 1822 engaged a Dutch gardener for Salm’s hortus. On more than one occasion Salm showed himself extremely grateful for all this help, often indispensable, such as Van Marum’s introduction of Salm to Haworth, England’s leading expert on succulents.
Early already in their relation, in 1815, Van Marum came up with the suggestion that Salm should make up and distribute a catalogue of his succulents collection. That would be the best way to find out what species he still was lacking. Salm agreed, and after some postponement due to waiting for some new species from England, French and German editions of his catalogue were printed in 1817.  Van Marum distributed 35 copies to his correspondents. There were updates in 1822, 1829, and 1843. We see that over the years Salm extended his succulents collection, to include the genera Mesembryanthemum, Cactaceae, Polonia, and Paeonia.
Van Marum was the elder of Salm by almost a quarter of a century. Their correspondence ended in December 1834. Probably Van Marum’s declining health – he was 85 by then – explains this.
Reinwardt (1773-1854) 
Caspar G.C. Reinwardt was a German who studied pharmacy in Amsterdam, and was appointed professor in that discipline at Harderwijk in 1801. (Harderwijk is a city near Utrecht, it had a so-called Athenaeum in those days. That was a university without the right to confer Ph.D.’s.) It was in those years that he got befriended with Van Marum. In 1806 the Dutch Republic became a kingdom under Louis Napoleon, younger brother of Napoleon. Two years later, Reinwardt was appointed Director of the Royal Botanical Garden, which included a menagerie and a natural history cabinet. When in 1810 the Kingdom of Holland was annexed by the French Empire, Reinwardt found a new job as a professor of pharmacy and chemistry at the Amsterdam Athenaeum.
After the end of the Napoleonic era, in 1814, Reinwardt was asked to join the Dutch mission to the East Indies, which was to take over the English administration. He accepted and was appointed Director of Agricultural Affairs, Arts, and Sciences. Neither more nor less! The mission sailed in October 1815. Reinwardt would stay in the Dutch East Indies until June 1822. He is the founder of the botanical garden and research station at Buitenzorg (now Bogor) on the isle of Java, where he gathered some 900 plants . In going to the tropics, Reiwardt took a huge risk to life and health, like everybody did who went there in those times. But look what was part of the challenge: for his professorship at Amsterdam he earned Dfl. 1,500 a year, while his yearly salary in the East Indies was no less than Dfl. 24,000, a sixteenfold increase!
In 1815, the year of Reinwardt’s departure, Van Marum comes into the picture, their correspondence starts. Van Marum had promised to take care of all of Reinwardt’s affairs in Holland during his absence: his finances, his properties, his family, all of these becoming sources of anxiety on several occasions. But the main affairs, off course, were things botanical: Van Marum was keen on receiving rare plants from Reinwardt, not only for Plantlust but also for the Hortus Dyckensis.
On the way to the East, there was a stay at the Cape of Good Hope. For several reasons Reinwardt saw no possibility of sending plants from there to Holland, but he expressed his hope to do so on his homeward voyage. He brought the garden owner and clergyman C. Hesse into correspondence with Van Marum, which resulted, in 1817, in a dispatch of plants, bulbs and seeds to Haarlem. On his return to Germany, Hesse presented all his living plants to Kew while promising Van Marum the duplicates, that he was to receive from Kew.
Once on the isle of Java, Reinwardt soon was as delighted with the tropical vegetation as he was pessimistic about shipping plants to Holland. In May 1816 he wrote that he had not yet seen any succulents and in fact did not expect them to grow there. He fears that the special growing habits and conditions of many of the Javanese plants, such as orchids, ferns, lianes, cauliflorous trees, and the many parasites, make it impossible for them to survive in Europe. However, these considerations did not stop Reinwardt from sending numerous shipments to Holland in the course of the years . Unfortunately, most of these shipments were ill-fated: there is a long list of shipwrecks, and in a leter of 1819 Reinwardt finds it hard not to get discouraged. Besides, of the shipments that reached Holland, almost all plants had dried out. It seems that captains were instructed to leave the plants alone and even refrain from watering.
Here is an example of such a shipment failure. Interestingly enough, it is related to Kew Gardens. In April 1817 a British mission to China, on its way home, harboured in Batavia (now Djakarta). Its physician and botanist was Abel Clark. Reinwardt gave him seeds, 25 Javanese plants, and 4 cases with fruit trees to take back to Europe. Kew was to have some of these, but Reinwardt stipulated that all single specimens should be sent to Van Marum. Until January 1818 Van Marum did not receive anything, no plants, no letter. Ultimately, only a packet of seeds arrived, without message. An angry Van Marum wrote to Clark, asking for an explanation. Clark replied in February: he denied that there was such an agreement between Reinwardt and himself, and stated that if the transport had been successful, he would have sent all the plants to Haarlem without delay, and without making a selection for Kew. But the course of events had been that the gardener who was to take care of the plants had stayed in Batavia, and soon the complete shipment of plants and trees, without proper care, had been eaten by the goats on board.
So, we need not to be surprised when we learn that in 1821 Van Marum had only six species of Javanese plants in his hot-house. To his regret, he even lacked a Marumia , a plant Reinwardt had named after him. Also, some plants had gone to the university gardens, with Van Marum as an intermediary. Anyway, from 1819 onwards, most plants were sent to the Leiden hortus. In that year Reinwardt got the confirmation that upon his return he would become a professor at the Leiden Academy.
Looking at the whole of Van Marum’s botanical activities, we find that his main work was as a succulents expert and collector. It may seem strange, then, that he did not publish anything on this subject. There are partial explanations, such as his many other activities. The most satisfying one, however, is that it probably was never his intention to do so, preferring a position in the background in this field, that also was much a hobby for him. Nevertheless, his normal industry also showed itself here, mainly in his intense and sustained help and support for Salm-Dyck.
Several times during the 1810’s and 1820’s Van Marum had the intention to publish an update or a supplement of his Plantlust catalogue of 1810. He never managed to do so. Instead, he used copies of the updates of Salm-Dyck’s hortus catalogue to indicate which species also were present in his garden. In this way, by making a virtue of necessity, he still was able to inform his correspondents about the development of his own plants collection.
Besides Van Marum’s use of Salm’s inventories, there was yet another aspect to their relation that made it a give-and-take affair: it is only in his letters to Salm that Van Marum clearly speaks about his ideas on descriptive botany. I shall finish now by giving a few examples:
He stresses the importance of monographies as opposed to the confusing mix-up of publications that troubles descriptive botany.
He opposes the tendency in the study of succulents to describe far too many species and varieties. Salm often was inclined to do so, and his hesitations in those cases now and then drove him to despair. For Van Marum, for instance, differences in form as the result of different cultivation, were no reason to create a new species or variety.
In matters of nomenclature, he did not want to give a plant a non-characteristic name, and he did not appreciate naming a species after a person. But in the same letter in which this is discussed, he takes a lenient view at the matter, admitting that often sense of honour, and vanity, prevail.
Also, the rule of priority was discussed. This rule means that when a plant genus or species is described under different names, the oldest one is valid. In practice, this rule made name changes unavoidable. Salm was a staunch adherer of this rule; in his opinion, sticking to it certainly now and then was inconvenient, but it always meant avoiding a greater inconvenience. Of course, also Van Marum liked uniformity in naming, as he was annoyed by the all too frequent changes of names. But in his opinion there should be room for improving and perfecting names, especially when working on complete monographies, like Salm was doing.