Here, my dear Master, are two more exercises: one is the follow-up to the Hypothesis; the other is in the form of a note to Our Lady of Auteuil. I am always delighted by your corrections, but as I see by those which you made near the end of the 22nd Article, I did not make myself clear enough to be understood. I think that it would be best to omit the last 5 or 6 lines, namely those which follow the word Electricity. You can correct your copy accordingly, as these lines are not necessary—There goes another exercise!—