Final answer:
M. Laval told the mayor of Montignac about the discovery. It's presumed that the context involves a historical event or discovery, potentially related to French exploration, settlement, or scientific advancements.
Step-by-step explanation:
The person M. Laval told about the discovery is presumed to be the mayor of Montignac. The context of the question is likely related to a historical event or discovery, which could be connected to the exploration and scientific contributions of the French, such as the voyages of Jacques Cartier, the founding of Fort Caroline by René Goulaine de Laudonnière, or scientific advancements made under the patronage of royalty, such as the works of the Academy of Sciences in France founded by Louis XIV.
It is also possible that the question is referencing a specific historical document or artifact that was discovered, and the mention of M. Laval could be related to someone involved in the recovery or reporting of such a find. Without additional context, it is challenging to determine the exact nature of the discovery or the historical period in question.