Up to this time the weather was all that could be wished, cooler, I suppose, than in England at the time. But that week at Philadelphia was raging. Mrs. Gray and I were there for the whole week, domiciled with friends in the heart of the city,--a city which never cools at night, as it does hereabouts. I bore the heat well, as my manner is; Mrs. Gray, fairly, by keeping quiet through the mornings and giving herself rather to the evening receptions, which were fine and most admirably managed. It grew cooler the moment the week was over and the session ended. Besides, we moved at once into a cooler region. It was arranged that I should lead any British botanists that cared to go on an excursion into the mountains of Virginia and Carolina. But they were otherways bound, so that I could take only my friend Mr. John Ball of London, your fellow F. R. S., taking also another American botanist, with whom we had visited these regions more than once before, and, to make it pleasanter, we added three ladies, wives and daughters of botanists, Mrs. Gray being one. Our first day’s journey was to Luray, in the Valley of Virginia, between the Blue Ridge and the proper Alleghanies. The next day we visited the Cavern, which I think is the finest in the world, not forgetting that of Adelsberg in Styria. It is newly discovered, with wonderful wealth and beauty of stalactical formations, and is lighted up for visitors with electrical lights in all the larger chambers. That day we went on to the Natural Bridge, which we had not seen for many years. It was grander than I had remembered; indeed, it and the scenery around is worth a voyage and a journey to see. Then we went on to our favorite Roan Mountain, on the borders of North Carolina and Tennessee, one of the highest in the Atlantic United States, and the finest; the base and sides richly wooded with large deciduous forest trees in unusual variety even for this country, the ample grassy top (of several square miles) fringed with dark firs and spruces, and the open part adorned with thousands of clumps of Rhododendron Catawbiense, which when there last before, late in June, we saw all loaded with blossoms, while the sides were glorious with three species of Azalea, not to speak of many other botanical treasures. There, at top and at base, we passed four busy days. A narrow-gauge railway recently built, and new to us, reaches to the base of the mountain, up the Doe River, through most picturesque scenery, showing to most advantage in the descent. On our way back we diverged to visit some striking rock scenery on the upper Kanawha River, and thence to a mountain-top lower than Roan, but with the advantage of a charming little lake, with banks all fringed with Rhododendron maximum and Kalmia, hanging over the water for a rod or two, except on the side where the little hotel stands. Well, I have written a deal here, little as I have managed to tell you. I think you and Lady Fry should come over