It was strange, Louis-Joseph would one day think, how a month could pass in both the blink of an eye and with the weight of an eternity. In those days of late 1784, he was not yet four years old, though his mind carried the gravity of an older soul. He remembered the cold of Versailles' stone corridors, the faint smell of wax and iron mingled with winter air, the way the courtiers' wigs seemed like clouds that never shifted. Yet he also remembered, most vividly, the workshop.
His father's workshop was no throne room, no chamber lined with gold leaf. It was an island of curiosity within the sea of ceremony—a room cluttered with tools, sketches, models, and the delicate dust of experiments. It was here that the King shed his majesty and became, for a time, a craftsman. Louis XVI would bend over a workbench with sleeves rolled up, eyes squinting through glass, murmuring in tones not of command but of inquiry.
And it was here, in the waning weeks of autumn, that Louis-Joseph saw how science could be bent toward life and death, not merely amusement. A microscope—so ordinary in later centuries—seemed then like an instrument of magic. It drew the invisible into sight, revealed tiny worlds crawling upon bread, wine, or a drop of blood. His father delighted in its use, testing lenses, polishing glass, insisting that no tool was too humble if it brought knowledge.
The Dauphin would one day recall the exact words: "The sharpness here is better, but the magnification has fallen. Try again." Or: "This new lens reduces colors, yes, but the image is too dark. The work is not finished." Such judgments fell not as edicts from a King, but as notes from a master craftsman guiding apprentices.
At the time, Louis-Joseph had thought such projects would take months, perhaps years, to reach their fullness even with his help. Yet scarcely had November begun when he found himself standing beside Parmentier, the celebrated savant of potato and nourishment, being drawn into experiments that reached far beyond flour and potatoes. For the boy, the speed of it all was astonishing. One day he played cards in his mother's salon; the next, he was listening to a discussion of gangrene, mold, and the invisible armies of decay.
That month between following would leave an imprint deeper than any court fête. It was the month when play became inquiry, when curiosity edged toward discovery. And though history would not yet record it, it was the month when the first shadows of a new kind of science flickered across the marble floors of Versailles.
The morning of November 11th was bright but brittle with frost. In the King's private workshop, the Dauphin stood beside his father, watching the older man adjust the polished brass of a new microscope. Several artisans hovered in the background—lens-grinders, instrument makers, their hands calloused but their gestures reverent in the presence of their monarch.
Louis XVI placed an old model on the bench for comparison. He peered first through one, then the other, before pronouncing judgment in his calm, deliberate voice.
"The sharpness is better here," he said, tapping the rim of the newer lens, "but the magnification has lessened. Recommence. We must not trade detail for clarity."
The artisans bowed, already murmuring among themselves about adjustments. The King turned, almost absently, and caught his son watching. A smile softened his face.
"You see, Joseph, even kings must argue with glass."
The boy laughed, though he only half-understood. What struck him was not the jest, but the earnestness with which his father spoke. Here was no pomp, no heavy etiquette. Here was truth spoken plainly, a lesson by example: the pursuit of precision above vanity.
It was later that same day that Antoine-Augustin Parmentier arrived. Known already for his tireless campaigns to promote the potato and to study nutrition, he was a man of practical genius. His eyes gleamed with curiosity when he beheld the microscope.
"Majesty, with such an instrument one could examine not only grains of flour, but the very rot that afflicts them," he said.
Louis XVI inclined his head. "And more than grain, monsieur. Anything could be..."
The King's words turned the conversation toward darker matters. Gangrene: that scourge of the battlefield, that silent enemy which killed more soldiers than bullets. The Dauphin listened intently as Parmentier spoke of rot, infection, the unseen agents that turned a cut into a death sentence. For a boy of three, it was a strange subject, yet his mind—sharpened by experience not of this century alone—grasped the import.
Within days, a protocol took shape, dressed in the language of play to soften its edge.
Step one: collection. Servants, artisans, even children of the kitchens were tasked with gathering scraps of mold—green fuzz from stale bread, blue veins from forgotten cheese, soft blooms from rotting fruit, earthy smears from garden soil.
Step two: testing. Parmentier, guided by the King's curiosity, prepared small animals—poultry, rabbits—for the trials. Tiny incisions, the kind common in such inquiries of the age, were made. To each wound, a different mold was applied.
Step three: observation. Day by day, the progress was noted. Some wounds festered, others blackened. But a few—strange, rare—seemed to heal more swiftly, resisting decay.
Louis-Joseph observed all with wide eyes. To him, it was both solemn and exhilarating: a game with rules, but a game whose prize was life. His childish voice, half in jest, called it "the race of mold." Yet beneath the jest lay a dawning awe.
Parmentier was quick to see how the boy's fascination could be guided. "Monsieur," he told him gently, "you who love order and learning, remember this: the smallest thing can be the most powerful. Bread feeds nations. A speck of rot may yet save them."
The Dauphin nodded, treasuring the phrase.
The weeks that followed were a tapestry of repetition and refinement. Each day, Louis XVI would test the latest glass, peering at fibers, droplets, crystals of salt. Each day, Parmentier compared notes, adjusting his method. The artisans shuffled in and out with new lenses, new frames, new alignments of brass and glass.
On November 23rd, the King declared with satisfaction: "Now the sharpness and magnification are in balance. At last we see more than shadows."
By November's end, the workshop smelled faintly of earth and rot, as samples piled up in glass vials. Notes filled pages—sketches of wounds, records of progress, careful charts of mold's strange variety. Louis-Joseph, too young to write in a steady hand, contributed with drawings: crude shapes of rabbits, circles labeled with crosses where the wounds had healed or blackened. His efforts earned a smile from Parmentier and a rare embrace from his father.
By December 5th, patterns began to emerge. Certain molds from bread seemed gentler, others from soil more violent. The boy watched Parmentier's finger trace the notes, and though he could not yet put it in words, he sensed that something immense trembled at the edge of discovery.
On December 11th, a month to the day since the experiments began, the King convened a small gathering in the workshop. Not courtiers, but artisans, Parmentier, and his son. He gestured to the microscope, polished until it gleamed.
"This," Louis XVI said, "is not a toy. It is a mirror to another world. With it, we may one day see the enemies that stalk unseen. And if we see them, perhaps we may defeat them."
The Dauphin, standing close, felt the weight of those words. It was more than glass and brass. It was hope. Hope that should be protected even from someone his father may trust, as he didn't trust his father's judgement of a human being.