Five of Euler's works, all extracts from letters, were published in the Philosophical Transactions.
Publications from 1748
E107: Extract of a letter from Mr. Leonhard Euler, Prof. Mathem. and Member of the Imperial Society at Petersburgh, to the Rev. Mr. Cha. Wetstein, Chaplain and Secretary to His Royal Highness the Prince of Wales, concerning the Discoveries of the Russians on the North-East Coast of Asia.
Publications from 1752
E183: Part of a Letter from Leonard Euler, Prof. Math. at Berlin, and F.R.S., to the Rev. Mr. Caspar Wetstein, Chaplain to his Royal Highness the Prince of Wales, concerning the gradual approach of the Earth to the Sun
E184: Part of a Letter from Mr. Professor Euler to the Reverend Mr. Wetstein, Chaplain to his Royal Highness the Prince, concerning the Contraction of the Orbits of the Planets
Publications from 1753
E204: Extract of a Letter from Professor Euler, of Berlin, to the Rev. Mr. Caspar Wetstein, Chaplain to Her Royal Highness the Princess Dowager of Wales
Publications from 1754
E210: Letters relating to a Theorem of Mr. Euler, of the Royal Academy of Sciences at Berlin, and F.R.S., for correcting the Aberrations in the Object-Glasses of refracting Telescopes