We have been so actively employed, I may really say so laboriously, that I assure you I can with great difficulty find a moment to write a letter. This morning we got off, after breakfast at five o’clock, on horseback, to return from St. Amand to this: arrived at seven o’clock. But one day we rode fifty-five miles, which I shall take care shall be the last experiment of that kind, as even the old Leicestershire fox-hunter was nearly done up with it. But I have really gained strength so much, that I believe I and my eyes were never in such condition before; and I am sure that six hours in bed, which is all we allow, and exercise all day long for the body, and geology for the mind, with plenty of the vin du pays, which is good here, is the best thing that can be invented in this world for my health and happiness. Murchison must have been intended for a very strong man, if the sellers of drugs had not enlisted him into their service, so that he depends on them for his existence to a frightful extent, yet withal he can get through what would knock up most men who never need the doctor. He has only given in one day and a half yet. On one occasion we were on an expedition together, and as a stronger dose was necessary than he had with him, I was not a little alarmed at finding there was no pharmacy in the place, but at last we went to a nunnery, where Mdlle. la Supérieuse sold all medicines without profit—positively a young, clever, and rather good-looking lady, who hoped my friend would think better of it, as the quantity would kill six Frenchmen. M. was cured, and off the next morning, as usual. The mischief is, that he has naturally a weak though a sound stomach, and if he possessed a more than ordinary share of self-denial, and was very prudent, and after much exercise did not eat a good dinner when set before him—if, in short, he would take the advice which many find it easy to give him, he would be well. He has much talent for original observation in geology, and is indefatigable, so that we make much way, and are thrown so much in the way of the people, high and low, by means of our letters of introduction, and our pursuits, that I am getting large materials, which I hope I shall find means of applying. Indeed, I really think I am most profitably employed on this tour, and as long as things go on as well as they do now, I should be very sorry to leave off; particularly as, from our plan of operation, which is that of comparison of the structure of different parts of the country, we work on with a continually increasing power, and in the last week have with the same exertion done at least twice as much in the way of discovery, and in enlarging our knowledge of what others had done, as in any preceding. I expect it will