Bishop and Physician (Wikipedia)
In December 1665, Lister met the Danish physician Nicolas Steensen, known as Steno (1638-86), who had published a treatise on muscle contraction and who was already known for his discovery of the duct of the parotid salivary gland (Steno’s duct). Steno and Lister performed a dissection of an ox head in the study of Robert Bruce, the First Earl of Ailesbury and Second Earl of Elgin.
Ailesbury evinced interest in natural philosophy throughout his life and was made a member of the Royal Society in 1685. Lister secured the introduction to the Earl due to his family connections to Sir Matthew Lister, his uncle; in his memoirs, Lister wrote, ‘I made my reverence to my Lord of Alsbury, who was infinitely civil to me upon my Unkle Sr. Matth. Listers memory’. Lister would assist Steno in four dissections in the Earl of Ailesbury’s study. In his memoirs, Lister praised Steno’s technique that was ‘neat and clever’ and admired his ‘genius and great personal modesty’, stating ‘I observed in him (very much) of the Galant and honist Man as the French say, as well as of the Schollar’. Lister was especially fascinated by Steno’s dissections of the lacteals in the intestines of a dog and his experiments with the passage of blood and chyle through the digestive system; in the 1680s Lister would repeat these experiments, collaborating with William Musgrave, the secretary of the Royal Society.
Steno also wrote a chorographic work of Tuscany, the Prodromus (1668), which was a bold assertion of the organic origin of fossils and how they came to be enclosed in layers of rock. He described a process in which juices seeped through cracks in the earth that were caused by the movement of geological strata. This juice dissolved mineral salts, penetrating interstices of animal shells, eventually replacing the shells with a stony substance.
When he returned to England, Lister would challenge Steno’s assertions. Lister argued that fossils were not always remains of living creatures, but could be created spontaneously by nature as part of her inherent ‘generative powers’. They represented the views of early modern naturalists who postulated that metals and minerals were spontaneously nurtured and generated in deep mines considered to be Mother Nature’s womb, and stones that resembled living creatures could be generated without any organic origins. As an eminent conchologist, Lister also realised that there were many fossil specimens that did not represent extant living creatures; as to countenance extinction was heterodox, Lister supposed these fossils were formed spontaneously by Nature.
Steno’s work was recently the subject of a Google Doodle in 2012, commemorating his 374th birthday. An article in the Washington Post explained the doodle: “The strata illustrate Steno’s ‘principle of original horizonality’, which essentially says that rock layers form horizontally — and only appear differently if later disturbances cause the deviation. And the fossils in the lower stratified rock help illustrate Steno’s ‘law of superposition’, which — simply put — says that the oldest rock layers are sequentially deposited on the bottom unless otherwise disturbed”.