From Today in Science History:
Nicolaus Steno. Born 10 Jan 1638; died 26 Nov 1686.
(a.k.a. Niels Steensen, or Stensen) was a Danish geologist and anatomist who first made unprecedented discoveries in anatomy, then established some of the most important principles of modern geology. During medical studies in Amsterdam he discovered “Stensen’s duct” providing saliva from the parotid gland to the mouth. He was Danish royal anatomist for 2 years. Interested by the characteristics and origins of minerals, rocks, and fossils, he published in Prodromus (1669) the law of superposition (if a series of sedimentary rocks has not been overturned, upper layers are younger and lower layers are older) and the law of original horizontality (although strata may be found dipping steeply, they were initially deposited nearly horizontal.)
(1660) On instigation of Thomas Bartholin Steno first travelled to Rostock, then to Amsterdam and studied anatomy under Gerard Blasius, focusing again on the Lymphatic system. Steno discovered a previously undescribed structure, the “ductus stenonianus” (the duct of the parotid salivary gland) in sheep, dog and rabbit heads. A dispute with Blasius over credit for the discovery arose, but Steno’s name is associated with this structure.Within a few months Steno moved to Leiden. There Steno met the students Jan Swammerdam, Frederik Ruysch, Reinier de Graaf, Franciscus de le Boe Sylvius, a famous professor, and Baruch Spinoza. Also Descartes was publishing on the working of the brain, and Steno did not think his explanation of the origin of tears was correct. Steno studied the heart, and found out it was an ordinary muscle.
In 1667, Nicolaus Steno, a Lutheran, converted to Catholicism and became a major figure in the Counter-Reformation.
He was beatified in 1988.
His Major Works:
- Anatomical Observations (1662)
- Concerning Solids naturally contained within solids (1669)
- Elementary Mylogical Specimens (1669)
- Discours de Monsieur Stenon sur L’Anatomie du Cerveau (“M. Steno’s lecture on the anatomy of the brain”, Paris 1669)
(N.B. Some list his birthday as the 1 January, and others as the 11 January)
Continuing with kvond’s posts at the blog Frames/sing – here are the articles in which Huygens is featured:
- Some Rough Thoughts On Spinoza and Technology – Continuing thoughts on the possible conclusions that can be drawn from Spinoza’s criticism of Huygens’ lens-grinding machines from letter 32 to Oldenburg
- Huygens’s Lens – a photo of the lens that Huygens’ used to discover the moon and rings of Saturn in 1655. The presence of an Ovid line on the glass is noted.
- Spinoza: Not As Abused As Is Said – the evidence for the presumed disparagement of Spinoza’s optical knowledge (and social standing) is questioned.
- What Spinoza and Huygens Would Have Seen – a brief research and imagination of what Spinoza and Huygens would have seen if they looked together at the night sky on a mid-summer date, in the village of Voorburg in 1665.
- Did the Huygenses “buy” Spinoza’s lens polishing technique? – a hypothetical account of how the acquisition of Spinoza’s lens-grinding equipment might have accelerated Christiaan Huygens production of the single lens microscope.
- Huygens’s Comments On Spinoza’s Theory of the Microscope to His Brother – a posting of the original French text of Huygens’s May 11 1668 letter to his brother, and some commentary on conclusions for Spinoza’s technique.
- Monconys’ Visit: Six Degrees of Separation for Spinoza – the importance of French diplomat Bathazar Moconys’ 1663 visit is fleshed out. This visit ties together some of the most signfiicant figures in Spinoza’s optical milieu, Hudde, Vossius, Huygens, (not to mention Vermeer at Delft) and attests to the pervasiveness of the single-lens, bead microscope design.
- Simple or Compound: Spinoza’s Microscopes – A discussion of the conclusions that may be drawn from Christiaan Huygens’ 1668 admission that Spinoza is correct that smaller objective lenses produce finer representations of objects.
- Spinoza’s Comments on Huygens’s Progress –letter 32’s observations on and objections to Huygens’ lens grinding machine are examined. Significant aspects of the Latin are retranslated, making more clear Spinoza’s point of emphasis, and opening of questions about whether Spinoza had extensive experience in polishing (or grinding) metal forms.
- Spinoza’s Lens-Grinding Equipment – A commentary on the likely source types for Spinoza’s grinding laps, given those used by the Huygenses, with a rough assessment of Spinoza’s place in the milieu local knowledge.
- To Understand Spinoza’s Letter 32 to Oldenburg – Various designs of Christiaan Huygens’s actual (and theoretical) lens grinding machines are shown to give better context to Spinoza’s description of, and objection to, the device he likely saw, as written about in letter 32. The issue of mechanistic complexity, the role of the craftsman, and Spinoza’s notion of liberation is broached.
- Traces of Spinoza’s Microscope – Evidence is cited that Huygens primarily used melted bead lenses, and a diagram is presented from Huygens’s notebook which may represent design elements of Spinoza’s microscopes purchased at the auction of his estate.
- The Text of van Gutschoven’s Letter to Huygens No. 1148 – a 1663 letter from the mathematician van Gutschoven which shows lens-grinding techniques for small lenses typical of the period.
kvond of the blog Frames/sing has an intensive look into the influence of optics on the metaphysics of Spinoza, who was a lens grinder by trade. Listed here, the articles in which he touches upon Leeuwenhoek:
Van Leeuwenhoek’s View of Technology and Spinoza – prospectively, a philosophical consideration of Van Leeuwenhoek’s refusal to show others his lenses, his methodology of examination and instrument design is put in relationship to Spinoza’s own likely merchant-class approach to optics and instruments. The powers of instrumentation and issues of specimen staging are brought together.
The Simple Microscope in the Hands of Van Leeuwenhoek and Huygens – A comparison between the rotary conception of the specimen viewing found in Christiaan Huygens microscope and the Van Leeuwenhoek idea of a ”staged”, fixed specimen, as it reflects a different idea of device and observation.
On the Issue of Clarity and Light: Van Leeuwenhoek’s Lenses – a 1685 quote by Thomas Molyneux is presented in support of the view that the lens polish of bead, single microscope lenses can have a determinative affect on distinctness and luminosity.