Your letter of Apr. 26. with the packet containing Marmontel & Cabanis are safely recieved. the work of the latter author brings to my knolege another of his, of which I had never before heard ‘de la certitude de la medecine.’ perhaps you may have this also in your collection, in which case I should be glad to recieve it. I shall be at Washington in the course of this week & shall hope to recieve there your catalogue. should it contain any thing more to my mind, I will ask it & remit the amount of that & the articles last furnished together. I salute you with respect.