Page - 224 - in Maximilian Hell (1720–92) - And the Ends of Jesuit Science in Enlightenment Europe

Chapter 5224 proceedings of the Society of Sciences in Trondheim, where priest Erik Ger- hard Schytte (1728–1808) reported from Lyngen, not far from Tromsø, that since in his experience “frozen sea water shines exactly like that which is not frozen,” no “insects” could possibly be the cause of the light. Instead, he surmised that morild was caused by fragments of bitumen, which the soil in that area was teeming with.47 The question was subject to a great deal of attention by the Arabia Felix expedition as well. Although the natural history diaries of Niebuhr’s associate, Pehr Forsskål (1732–63), had not yet been published, Hell may well have discussed the topic in his meetings with Niebuhr in Copenha- gen during the northbound part of his journey. In any case, Forsskål was trying to find the cause of morild during the sea voyage soon after the expedition ship had left Copenhagen. Unable to find any trace of animals in the water samples, even when sieved through cloth as in the example from Venice, Forsskål con- cluded that the luminescence was probably caused by “the slimy residue of jellyfish.”48 During the dark winter nights of 1768, Hell and his associates noticed that the Arctic Ocean sometimes proved to be luminescent. Accordingly, they took samples and performed tests similar to those described in Pontoppidan’s book. They found—correctly—that the light in the sea around Vardø was caused by “quite small sea insects, no greater than an average flea, indeed far smaller than that” and visible only in the microscope.49 Hell describes his experiments in various letters from January 1769.50 In a particularly elaborate letter to Gunne- rus, he confesses that earlier he had been convinced that morild was caused ei- ther by electricity or by pieces of minerals floating in the water, as argued by Schytte. However, when experimenting with the sea water in Vardø equipped with cloth, a microscope, and distillation apparatus, he managed to come to the conclusion that the tiny “sea insects” were the real cause of the phenomenon. 47 “Verschiedene Anmerkungen an den Bischoff in Drontheim,” Der Drontheimischen Gesell­ schaft Schriften Erster Theil (1765), 242–49 (quotations on 249). 48 Lawrence J. Baack, Undying Curiosity: Carsten Niebuhr and the Royal Danish Expedition to Arabia (1761–1767) (Stuttgart: Franz Steiner, 2014), 96. See further, E. Newton Harvey, A His­ tory of Luminescence from the Earliest Times until 1900 (Philadelphia: American Philosoph- ical Society, 1957), 522. 49 Draft of letter from Hell to Gunnerus in Trondheim, dated Vardø, January 15, 1769 (wus; most of the letter is published in Pinzger, Hell Miksa, 1:59–62). In Norwegian waters, the cause of morild is usually species of the genera Noctiluca, Gonyaulax, or Ceratium, all ani- mal planktons never exceeding two millimeters in size. 50 Hell to Schøller in Trondheim, dated January 12, 1769; to Pilgram in Vienna, dated January 15, 1769; to Horrebow in Copenhagen, January 15, 1769; to Peter Tønder Nordal in Trond- heim, January 16, 1769 (all drafts, wus). The investigations of the cause of morild are also mentioned in Sajnovics’s travel diary, draft version (wus), on December 9 and 10, 1768.