I attended a meeting of the Institute this afternoon. An election of a correspondent took place, which ran very close between Charles Buonaparte and Agassiz, but the latter carried it!

I must not forget to tell you about the Loganiaceous plant from Florida, for so Decaisne, to whom I gave leave to sacrifice a flower for drawing, has determined it to be; so Brown’s hint is confirmed. There is something rather queer about the style, which, as Brown’s “Prodromus” is not before me, I cannot say is also the case in any of the subgenera or genera he has indicated.

Euploca, Decaisne says, is certainly apocyneous. Nuttall, I believe, places it in Boragineæ.

April 9.—I heard Mirbel lecture to-day, commencing his course at the Sorbonne. He is a very good and clear lecturer, of the colloquial sort, and illustrates very well by rapid sketches on the blackboard. I believe you did not see him. In the contour of his features and in expression he is a good deal like Dr. Peters, except that his countenance is more attenuated, his features small and very little prominent, and his complexion light. At the Ecole de Médecine I was not fortunate enough to hit the chemical professor. I heard a portion of a lecture in the anatomical theatre, but soon came away.

I have had another fine lesson from Mirbel. He showed me all the drawings of the paper, of which I send three copies. I quit to-day.

Lyons, Wednesday evening, April 17, 1839.

At six o’clock precisely the malle-postes for every part of France began to leave, one after the other: that for Lyons came up; our baggage all in, our seats selected and arranged for us, in ten seconds we were in our places, and before the word adieu was fairly beyond my lips we were off at full speed. We took the route by Burgundy, passed Sens in the night, breakfasted at six next morning at Auxerre, and during the day should have passed through Autun, but I believe we did not; passed Châlons-sur-Saône at dusk, and arrived at Lyons at six precisely the next morning,—a rather fatiguing ride, but I saved much time over the diligence, which would have been even more fatiguing. The mail-coach takes four passengers only, three inside and one with the conducteur; it is drawn by seven horses guided by a postillion, in boots almost as high as himself, and the horses are changed every five miles or thereabouts. The time it took to change the horses I believe never exceeded a minute. I timed them once or twice by the watch, and we were moving again before the expiration of the minute. The country through which we passed was more fertile and in better cultivation than what I saw of Normandy; it was beautiful but monotonous, except the latter part, which grew quite picturesque as we approached the Rhone and the rivers that fall into it....

Lyons is finely situated just above the confluence of the Saône and the Rhone, occupying the space between the two rivers and also the other bank of the former. It has two beautiful and very steep hills, between which the Saône winds, which add much to its appearance....

April 25.—I broke off here some time ago, and left a space which I intended to fill up the first spare moment, by telling you what I saw at Lyons; what kind of a town it is; how I might possibly have seen Mont Blanc from it had it not been a rainy day; how I called on Seringe,[89] saw the little botanical garden, took notice of many little contrivances, particularly the way he keeps the aquatic plants wet; how he went with me to the Académie of Lyons, the branch of the University of Paris.... I could also describe the manufacture of velvet, which I also saw, but for all these things time does not permit; a good opportunity of sending to New York occurring to-morrow morning. So I must leave the hiatus....

I was called this morning at a quarter before four; went down to the steamboat, which was to start promptly at five, but which did not until half an hour later,—a narrow comfortless vessel, with no awning or protection for the decks, in which point, and in the lack of all comfortable arrangements, it is just like every other steamboat I have seen since I left New York, those between Liverpool and Glasgow alone excepted. The Rhone, even at Lyons and far below, merits pretty well the epithets applied to it, where it “leaves the bosom of its nursing lake,”—“the blue rushing of the arrowy Rhone,” for it is rapid the whole course. At Lyons it has a blue tint like that of the ocean, though not so deep. Well, we were off at length, and aided by the current we made very satisfactory progress. The distance by post between Lyons and Avignon is one hundred and sixty-seven miles, but including all the turnings of the river it must be much more; however, at six o’clock and a quarter the spires and battlements of Avignon, lighted by the setting sun, were in sight, and a beautiful sight they were as we drew near. The wall of the city, built by Pope Innocent VI. in the twelfth century, is still perfect, and very pretty, the architecture being what I should have thought. Moorish (judging from pictures merely); the numerous spires of this very ecclesiastical town rising above it; the huge rocky elevation next the river,—the site of the ancient fortress, and of old temples, churches, etc.,—and not least the ruined bridge of very ancient date, that still throws its beautiful arches half across the river, the lovely Italian landscape around, so fresh and green, the distant mountains encircling the whole, made it altogether as delightful a scene as one could wish to behold. But you must know that I am now in the region of the olive and myrtle, and have in the short space of three days concentrated, as it were, the pleasure we experience in watching the gradual approach of summer. The season is said to be later than usual at Paris; it is like April in New York,—a few warm days, but the evenings all chilly and most of the days raw and unpleasant, The horse-chestnut trees of the Tuileries were just bursting their buds; but every hour since, and particularly to-day, I have noticed little by little the advance. Here nearly all the trees have assumed their foliage,—that pure and delicate vernal foliage which we always so much admire, but which you enjoy very much to come upon in the way I have done, instead of waiting week after week, with every now and then a snowstorm, just to keep winter in remembrance. But I must not forget that I have seen snow also to-day. The summit of Mont Ventoux, which we have had in full sight since twelve o’clock, is covered with snow, its brilliant whiteness contrasting finely with the craggy brown mountains of lesser elevation, as with the green fields and tender foliage of the valleys. There is nothing very grand in the scenery of the Rhone from Lyons to this place. The upper portion is very much like the Hudson between New York and the Highlands, but I think scarcely as fine, if you make due allowance for the effect of the old villages, etc. (not half so comfortable as ours surely, but much better adapted to improve the beauty of the landscape), with now and then a gray ruin, which is a vast improvement. But from Tournon quite to Avignon, the scenery quite surpasses the Hudson, and exhibits such variety, moreover, that you are charmed continually: now bold and magnificent even; again, picturesque, particularly where the basaltic rocks, for it is wholly a volcanic country, form parapets like the Palisades, but much more curious and diversified, the more friable material being worn away in places, leaving columns and salient portions in all fantastic shapes. And again, especially in the lower portion, we see the hills widely separated, leaving most beautiful broad valleys between, with high mountains for a distant background. At St. Esprit we passed under the curious old bridge built in the eleventh century, which is still in as perfect a state apparently as if finished but yesterday. It is three thousand feet long, and is said to be the longest bridge in Europe; it consists of twenty-six arches, and each abutment has also a little arch above it. We passed other very pretty or striking views of which I should like vastly to have good prints, but I do not know whether any person has of late been illustrating the Rhone. But I must come to a close, not to fatigue you longer. I arrived at the most excellent Hôtel du Palais Royal (recommended by Bentham) just in time for the table d’hôte at seven o’clock, and after dinner sallied out, with a guide to conduct me to see Requien,[90] to whom Bentham had given me a letter. I found him a prompt man, and in almost ten words we settled my plan for to-morrow, which is to start in a cabriolet for Vaucluse at five o’clock in the morning, arrive at eight, spend two hours, breakfast, and return here by one o’clock; spend the afternoon and evening in seeing the most interesting objects in town, looking at his collections, his pictures, etc., etc. What would you give to see Vaucluse? I have many doubts whether it will equal my expectations, which are raised by the description; according to the account it must be very curious and strange, apart from the associations of the place, which here pass for little with me, as I feel no interest at all in Petrarch or Laura, whoever she may have been.