I am anxious to know how far we can economically use the post for the transmission of printed matter. Perhaps I could safely send you “Silliman’s Journal” in this way. As an experiment I now send you our University catalogue. No, it will not do, I see, for anything weighing over two ounces or three. Beyond this the rates increase woefully.... TO GEORGE ENGELMANN. 18th October, 1855. Yours of August 30th (answered by my wife) was written when I was one day at sea. Yours of October 13, which arrived to-day, was written two days after I reached home again. I had two very pleasant voyages, on the whole, and not long, ten and a half and eleven and a half days; eleven days in Paris (where I was detained a little by a severe cold on my lungs) and a week in England, mostly at London and Kew. I found my brother-in-law so convalescent that I might have stayed at home, and I brought him home with me in good condition. We had hoped, till the last moment, to get places in the steamer of the 13th October, and to have had a fortnight more in England. But all the places had been engaged for months, and nobody was giving up berths up to the time we sailed; so we had to come in steamer of the 29th ult., where we got a good stateroom by great luck, though the vessel was greatly crowded. Dr. Joseph D. Hooker (whom I had wanted to see for some time) being away in Germany, and time being extremely valuable to me here, I was on the whole very glad to get home. The naturalists at Paris were en vacance, and mostly away. I saw only Brongniart, Spach, Gay, Dr. Montagne, and Trécul (who sent, I believe, some pamphlets for you; the package is not yet unpacked), and my good friend Vilmorin. Boissier was there from Geneva. In England I spent all the little time I could command at dear Hooker’s at Kew; and Bentham, then in the country, came down to see me. I made a long and interesting call on Robert Brown, who is very old, but full of interest. I shall not again see this Nestor of botanists, as well as facile princeps, in this world. Hooker was much delighted when I told him you were coming next spring to see him at Kew. He insisted upon taking me over to see the Cactus house, and all through it, so that I might tell you what a mass of Cacteæ there are there; and he will be much pleased to have you work among them. He spoke about his Cuscuteæ, but was not at all displeased at your retaining them; begged you would work them up if possible before returning them. You will be charmed with Sir William when you see him.