Botany

Kircher’s magnetism included not only the Earth and minerals, but the plants which grew from it. For Kircher, his bio-magnetism had been an important milestone in his academic career, with his Avignon sunflower clock garnering him interest and notoriety among scholars of his college. It remained an interest, and one that he spent time exploring in Magnes. He stated at the beginning of his chapter “De Magnetica facultate Plantarum” that “plantis summam cum Magnetis operationibus affinitatem esse, inde luculenter pater, quod motum magnetis perfectem imitentur (plants have a great affinity with the operations of the loadstone, because they imitate the motion of a loadstone perfectly),”^[1] finding three main classes of magnetic plant movement which corresponded to the properties of a loadstone. The upward growth of shoots and the downward growth of roots echoed the north-south polarity of a magnet; the ability of a plant to diffuse its fragrance and shoots in a geometric pattern demonstrated its similarity to the radiation of a magnet’s power in a sphere; and finally, a plant’s inclination towards its source of light was the same as how a loadstone aligned itself with the Earth’s poles.

The plant’s polarity was oriented not from north to south, but from the heavens to the earth, with the sprouts of a plant always orienting themselves to grow towards the air and the sky, and the roots always reaching down. Kircher determined it was an inherent property to the plant, just as it was to a loadstone, drawing a comparison between the splitting of a loadstone and the grafting of a willow tree. If a loadstone was cut in two, the two new pieces would each have a north-south polarity. Similarly, if a cutting was taken from a willow tree and planted, the cutting would grow roots and the branch would grow towards the sky, rather than continuing in the direction it was on the tree. A second element of the polarity of plants could be observed in the rings of a tree. These rings and veins in the tree trunk functioned as the botanical equivalent of the pole lines of a magnet and were so arranged to keep the tree aligned with its place in the universe, keeping it aligned on the natural axis of sky to earth.^[2]

The intangible range and effectiveness of a loadstone found its analogy in the pollens and fragrances of plants. The scent emitted from plants had a clear range with the strength growing as one approached the plant. This was determined to be similar to how the strength of a magnet would diminish the further one was from the magnet. Even the varieties between species were similar to how the purity or size of a loadstone would affect its magnetic strength. As a loadstone could draw iron to itself, so too could certain plants draw in other plants, and it functioned via the emission of unseen gasses. A few of Kircher’s examples of these attractive and repulsive plants included ivy – which was attracted to all trees – and a natural animosity between grape vines and cabbages which would wilt in the presence of one another. Kircher’s final application of magnetic radiation to plant life was the phenomena of fertilization. He believed that pollen was emitted from the male flower and magnetically attracted to the female. Environmental factors would impact the efficacy of the radiation, wind increased the sphere of influence, but ultimately the effect was due to magnetic radiation. Kircher’s example in this case was farming practices of Sicilian fig farmers. The species of fig grown for harvest would not bear fruit unless wild figs were planted nearby. The wild figs would fertilize the domesticated ones, but only the trees within a certain range. This proved to Kircher that the mechanism of fertilization was dependent upon proximity to the fertilizing plant, and this in turn was a function of magnetic radiation.^[3]

Finally, Kircher found that the attraction of a plant towards the sun, heliotropism, or the moon, selenotropism, was analogous to how a loadstone would endeavor to align itself with the poles, and when moved, would return to this alignment. That plants would follow the sun was by no means a novel observation, but the explanation, and Kircher’s application thereof, was. There were several elements unique to plants. That plants could follow the path of the sun, even with thick cloud cover demonstrated that the attraction was of a spiritual nature, not a material one. Additionally, a magnet would be reduced to immobility when perfectly aligned with its poles, but this alignment in plant life necessitated constant diurnal movement. Inspired by this constant movement, the sunflower clock was born. The conceit of Kircher’s invention was that utilizing the inherent magnetic properties of a sunflower, one could create a self-sustaining clock which could accurately relay the time, without need for human interference or direct sunlight. It consisted of a sunflower which was attached to a floating cork with its roots submerged in a tub of water. The water would allow the flower to turn as needed. A ring inscribed with hours was attached around the flower, and a pointer was attached to the middle of the flower, allowing the pointer to move to the different hours as the sunflower moved during the day. Kircher had also developed a system for adjusting the clock based on latitude.^[4] Unfortunately, the setup proved to be too delicate and unstable to make this a sustainable system of timekeeping, but its ingenuity impressed, with its observers writing to acquaintances of the invention, including, notably, two letters written by abbot Jean Jacques Bouchard to Galileo.^[5]

In explaining why some plants were heliotropic and other selenotropic, Kircher turned to Aristotle, further bringing classical philosophies in line with his usage of magnetic properties. In a heliotropic plant, the warmth of the sun would expand its internal humors and the flower and leaves would unfurl. Selenotropic plants were colder and wetter, and thus the energy of the sun would shrivel the humors and they would expand again under the moon. In addition to his exploration of Aristotelian principles, he also expanded upon the roles of other ancient philosophies, especially Hermetic traditions, by postulating that certain plants were connected to other celestial bodies beyond the sun and the moon. He was not certain which plants were affected by which bodies, but he theorized their connection would impact medicinal properties especially. Most plants were more strongly attracted to either the sun or the moon, but this was an attraction inherent to all plant life, even if the effects were more strongly seen in various plants.^[6]