816.363.4600
  • Facebook
  • Twitter
  • Linda Hall Library Tumblr Link
  • Linda Hall Library Vimeo Link
  • Linda Hall Library Instagram Link
  • Facebook
  • Twitter
  • Linda Hall Library Tumblr Link
  • Linda Hall Library Vimeo Link
  • Linda Hall Library Instagram Link
  • Contribute Now
  • Sign up for e-News
  • Online Catalog
  • Document Delivery
  • Digital Collections
  • Arboretum
Linda Hall Library

Search


  • Visit
    • Hours & Directions
    • Tours
    • Arboretum
    • William N. Deramus III Cosmology Theater
    • Using the Library
  • Public Programs
    • Lectures and Symposia
    • Past Lectures and Symposia
    • Lecture Videos
    • STEM Quizzes
    • Paul D. Bartlett, Sr. Lecture
    • Previous Speakers
  • Exhibitions
    • Current Exhibitions
    • Online Exhibitions
    • Past Exhibitions
  • Research
    • Online Catalog
    • Research Guides
    • Collections
    • History of Science
    • Fellowships
    • Difficult to Find Engineering Papers
    • Digital Collections
  • Services
    • Document Delivery
    • Image Reproduction
    • Reference Services
    • Using the Library
  • About
    • About the Library
    • Hours & Directions
    • Board of Trustees
    • Staff Directory
    • Employment Opportunities
  • News
    • In The News
    • Scientist of the Day
    • Sign up for e-News
    • Hedgehog
    • Annual Reports
  • Support Us
    • Financial Donations
    • Book Donations
Select Page

Scientist of the Day - Abbe de Vallemont

September 10, 2018

Engraved title page, Vallemont, La Physique occulte, 1696.
Linda Hall Library

Pierre Le Lorrain, the abbé de Vallemont, was born Sep. 10, 1649.  In the summer of 1692, a wine merchant of Lyon and his wife were murdered, and when the authorities were stymied, it was suggested that they call in Jacques Aymar, a master of la baguette. A baguette was a divining rod, a forked stick made of hazel wood that had been used for centuries to locate underground water and veins of ore.

Linda Hall Library

Aymar wielded his baguette in a different fashion. He used his rod to reconstruct crime scenes (he was able to point to the exact spots where the two victims lay), and then he led police on an extensive trail to a nearby town where his baguette fingered a young hunchback, Joseph Arnoul. His two accomplices had fled to Italy, but Joseph was taken back to Lyon, where he confessed to the crime and was then executed.

Absolutely no one at the time disputed that Aymar was able to detect traces of blood with his divining rod and that he had led the police to one of the killers. But how did the baguette work? – that was a much more lively question. In the previous century, most agreed that the divining rod worked by some sort of natural magic, so that the hazel wood might have a sympathetic attraction to water, or to metal, and respond accordingly. But in the last half of the 17th century, occult forces such as sympathies were losing favor, and the mechanical philosophy was rapidly gaining ground.  According to the principal author of the mechanical philosophy, René Descartes, the world is made of various kinds of inert matter, and all motions are the result of mechanical interactions of matter pushing on matter.  Even magnetism could be explained as the global circulation of invisible particles.

Linda Hall Library

There were no sympathies or magical effects in the mechanical world of Descartes and his followers.

Valllemont was a Cartesian. He believed in Aymar’s dowsing abilities – in fact, he interviewed Aymar extensively – and he had no doubt that Aymar had successfully tracked down a killer with his baguette. But there had to be a mechanical explanation. Vallemont proposed that humans leave behind corpuscles wherever they go, shedding them rather like skin cells, and wounded humans even more so. These blood particles are therefore detectible, and just as the eye is an organ for focusing and detecting light particles, a baguette focuses particles of blood, or water, or minerals, and a dowser is someone who is able to detect their presence. A divining rod is not an implement of magic; it is, in the right hands, just a particle detector, as the image below dramatically illustrates.

Linda Hall Library

In 1693, Vallemont published his Cartesian account of the divining rod: La physique occulte; ou Traité de la baguette divinatoire (Occult Physics, or Treatise on the divining rod).

Linda Hall Library

We have this book in our History of Science Collection, and much of the foregoing is an attempt to explain why a science library has a book on divining rods in its collection. We also have the 1696 second edition of this book, and since it opens better than the first edition, all of the images here except the title page are from the second edition.

Dr. William B. Ashworth, Jr., Consultant for the History of Science, Linda Hall Library and Associate Professor, Department of History, University of Missouri-Kansas City. Comments or corrections are welcome; please direct to ashworthw@umkc.edu.

 

RSS NOTIFICATIONS

  • Untitled

UPCOMING EVENTS

  1. War Fare: Modern Food, Moral Food

    January 21, 7:00 pm - 8:00 pm
  2. The Art and Science of Distillation

    January 27, 7:00 pm - 8:00 pm
  3. Kansas City Invention Convention

    April 29, 6:30 am - 8:30 pm

View All Events

Policy

  • Terms and Conditions
  • Library Rules
  • Privacy Policy
  • Acceptable Use Policy

Quicklinks

  • Online Catalog
  • Research Guides
  • Staff Directory
  • Employment Opportunities

About the Library

The Linda Hall Library is the world’s foremost independent research library devoted to science, engineering, and technology.

Library Hours

Monday - Friday
10:00 a.m. - 4:00 p.m.
Phone: 816.363.4600
Toll Free: 800.662.1545
  • Facebook
  • Twitter
  • Linda Hall Library Tumblr Link
  • Linda Hall Library Vimeo Link
  • Linda Hall Library Instagram Link

Linda Hall Library, 5109 Cherry Street, Kansas City, MO 64110-2498
© 2021, Linda Hall Library, All Rights Reserved