# Pasteur’s Alès silkworm mission begins amid already ruined Cévennes harvests

Date: 1865

## The fact

On 6 June 1865 [Louis Pasteur](/people/louis-pasteur) arrived at Alès at Jean-Baptiste Dumas’s urging to study silkworm disease, entering a Cévennes economy already stripped by years of pébrine. Rearers burned or abandoned stock under official and expert pressure while the laboratory learned. Early Pasteur guesses were wrong for whole seasons. The later published method is the improving industrial row.

## Context

Cocoon income had already fallen by a large factor before Pasteur packed. He did not invent pébrine. What he did was insert a Paris expert, a microscope, and experimental constraints into households that lived by the worm. His family came too. Do not pretend the 1870 volumes erased the 1865–67 losses.

If a number is not in the two records named above, it is not supplied here.

## Evidence and sources

Institut Pasteur at https://www.pasteur.fr/en/institut-pasteur/history dates the silkworm years as a government-scientific mission, not as a peasant memoir. Science History Institute at https://www.sciencehistory.org/education/scientific-biographies/louis-pasteur/ independently describes the 1865 Alès start and the long failure of French sericulture that preceded it.

Official or archival record: Institut Pasteur — History (https://www.pasteur.fr/en/institut-pasteur/history; Institut Pasteur).

## Significance

Inequality path: expert trial costs on already poor rearers. Medium confidence on how much extra loss the protocols added versus the blight itself. The 1870 method remains a different sign on a different row.

Later competitions, monuments, translations, UNESCO listings, museums, and adaptations are not converted into extra lifetime acts.

## What is established and what is not

Established: Pasteur began the Alès work on 6 June 1865 in a collapsed silk district. Not established: a unique franc total of household losses caused by his protocols rather than by Nosema. Contribution is recorded as He accepted Dumas’s mission and imposed experimental protocols on rearers. The blight predated him; local households took the harvest loss. Complex. The impact note is Experimental seasons laid on a collapsing peasant industry distributed loss downward while Paris science extracted a method, an inequality path of medium confidence. The dated heading stays Pasteur’s Alès silkworm mission begins amid already ruined Cévennes harvests on 1865-06-06, not a later statue, UNESCO listing, or school film. Printers, unnamed clerks, and later editors may appear in the same file without becoming this instrument.

The attached driver is [income-inequality](/drivers/income-inequality). The welfare reading used in this dossier is worsening. That reading is an impact-path choice, not a property stored on the Fact itself.

Confidence is stated on the impact path, not hidden in adjectives. The mission’s first day is not the 1870 Études. Mixed effects of Pasteur’s Alès silkworm mission begins amid already ruined Cévennes harvests are separate paths.

Shared responsibility is part of Pasteur’s Alès silkworm mission begins amid already ruined Cévennes harvests. Naming Louis Pasteur does not delete co-authors, institutions, or later transmitters. The lag from 1865-06-06 to any measured indicator is not treated as zero. Alternative explanations — weather, other armies, later statutes, or independent cultural change — remain live where the sources do not close them.

## People

- Louis Pasteur: https://factrail.ai/people/louis-pasteur

## Drivers

- Income Inequality: https://factrail.ai/drivers/income-inequality

## Sources

- https://www.sciencehistory.org/education/scientific-biographies/louis-pasteur/
- https://www.pasteur.fr/en/institut-pasteur/history

## Methodology

https://factrail.ai/methodology

Canonical: https://factrail.ai/facts/pasteur-ales-silk-1865