As most of you know, the cave was named after Molnár János (this is the Hungarian name order, Molnár was his family name and János is his given name), the chemist who worked in the 19th century. He was born in 1814 and got his pharmacist degree in 1838. He worked in a pharmacy, and he had a lab where he helped the investigations of the police as a forensic scientist in the city of Pest. Besides his everyday work, he was interested in biology, mineralogy, geology and published many scientific papers.
He was a well-known expert in the hot springs of Budapest and Hungary. He analyzed the water of many thermal baths and springs. The most exciting study from Molnár János for us was published in 1859. He gave a lecture in 1858 and after its success, he wrote an article to the yearbook of Magyar Királyi Természettudományi Társaság (Hungarian Royal Society of Natural Science). A Lukácsfürdő Budán (The Lukács Bath in Buda) is a detailed study about the different hot and warm springs of the Lukács Bath. Although the area is well known about these springs since the Roman era, he was the first scientist to work here.
Those who visit the Molnár János Cave can see the lake (Malom-tó) at the entrance, a hill above the cave (Józsefhegy), and the opposite side of the street the Lukács Thermal Bath. In the 19th century, these all belonged to the Lukács Bath, so in the study, Molnár János wrote about the actual bath and the lake with its surrounding area as well. (You can see it in the attached 19th-century artwork.)
For us, the latter is the more exciting. Molnár examined the different hot springs and he discovered there is a colder and a warmer spring and their water feed the lake. They drained the lake so they were able to explore the tunnel behind the lake. He tried to find the spring itself but discovered the tunnel continues in the water-filled cave- he realized the water had to come from somewhere else. He measured the amount of water flow too.
There was a recently discovered crack in the hillside of Józsefhegy and Molnár János with his helpers explored in the small cave which was a few meters above the water level of the lake. They found the water inside the cave (they simply threw rocks and they heard the splash of the water). One of his brave colleagues descended in the small cave and saw the water by himself, but couldn’t see the end of the cave with his lamp. So they thought there must be a huge cave inside the hill and were amazed by this discovery.
In the study Molnár János published all of his findings: he wrote about the different water samples, the water temperatures, he made drawings of the lake and the small cave in the hillside (you can see those in the attached pic, maybe these are the first known maps of the cave). And he had a suggestion: he thought it would be useful to open a passage inside the hill to the water-filled cave. Certainly 160 years ago he didn’t think about the diving explorations but anyway, he was the first who thought there are many things to discover there. He emphasized the importance of the protection of this “natural treasure” as he called it.
Whenever we visit the Molnár Janos Cave we can remember the great scientist who was the first to explore thoroughly this area.
(Source of the Pictures: Arcanum Digitális Tudománytár)