In a letter dated October, 1852, addressed to the President of the American Philosophical Society, Michaux expresses himself in the following words, with regard to his Sylva Americana: "The science of botany was the principal object of my father's explorations in North America, and the Flora Boreati-Americana was the result of those explorations. As for me, I took another view of the vegetable kingdom whilst in your country - a view more limited and less scientific, it is true; but, perhaps, more generally profitable to the farmer and landholder, as well as to that class of society, so numerous in the Northern States of the Union, who employ wood in so many different ways. I do not consider my Sylva Americana as complete as it might be; thus, for instance, I have omitted several species which grow in Lower Louisiana and in the two Floridaa. In the second place I have described and figured some trees that are deficient in the flowers and in the fruits. Had circumstances permitted, I would have returned to the United States, and, in a new edition, have corrected the errors, and filled up the omissions.

I would thus hare been able to present to the American nation a work worthy of her great name; but now that I have arrived at a very advanced age, nearly 83 years, I can do nothing more, in this respect, than to express my regrets and the hope that some native arboriculturist may complete my researches on the plan which I have adopted. The publication of such a work would be attended with much benefit to the country, and afford particular honor to him who would undertake it"

Since the appearance of his great work, Michaux has devoted all his attention to his favorite pursuits - the cultivation and propagation of trees presenting a special object of public utility. Intrusted with the administration of a large estate belonging to the Central Society Of Agriculture, experimenting largely in sylviculture on the extensive plantations of Mr. Delamarre, and owning himself a country place near Pontoise, he never ceased, until his death, to be actively employed in experiments on arboriculture, either suggested by himself or others.

Michaux had retained in this country a few correspondents, who sent him occasionally new supplies of seeds, and, through a letter furnished by one of these gentlemen, I had the gratification to become acquainted with him in the autumn of 1824.

When living in Baltimore, from 1816 to 1824,1 formed an intimacy with a French gentleman of the name of Leroy, who had known Michaux in this country, and had been since in correspondence with him. This Mr. Leroy, who was himself an excellent arboriculturist, having been earnestly solicited by his friend to send him all the seeds and young trees which he could procure in the vicinity of Baltimore, applied to me, as a fellow botanist, to assist him in this undertaking. We therefore went to work together in earnest during the autumn of 1819, rambling into the woods with a negro boy, climbing and beating Oaks, Maples, and Hickory-trees; uprooting the shrubs and young trees that fell in our way, and collecting seeds of every sort. The result of our campaign filled up several large boxes, which were forwarded to Michaux in the early part of the winter.

When I visited Europe in 1824, Mr. Leroy favored me with a letter of introduction to his friend, recommending me as his colaborer in the collections which had been forwarded to him from Baltimore some years previous. This letter did not fail insuring to me a hearty welcome at the hands of Mr. Michaux. I saw him frequently, and breakfasted with him at his winter quarters in Paris, on the place St. Michael, which was then a market for garden vegetables and fruits. We seldom sat at the breakfast table without having previously made an inspection through the stalls where fruits and vegetables were sold; and he was pleased to point out to me the rarest and most beautiful, with a passing notice on their origin.

Mr. Michaux was extremely desirous to show me in detail bis fine nurseries, especially those which contained his Maryland trees, to "contemplate" the result of the troubles and fatigues which they had cost me; but the weather was so unfavorable during the whole season that I could visit but one of them, which I found wholly planted with Maryland Oaks, and covering an extensive plot of ground. Though the young trees, then devoid of their foliage, had suffered much the second year from the depredations of a herd of swine that had trespassed upon the grounds, they still appeared vigorous and promising, and are, I suspect, the very same trees that are now (as I see by the Paris papers) adorning the Qoai des Taileriee, and some of the new boulevards of the French metropolis, under the denomination of American Oaks thirty-six f/ears old.

In acknowledgment pf the services I bad thus rendered him, Mr.'Michaux presented me with a copy of the French edition of his magnificent work, beautifully bound, in three volumes, and containing a double set of plates, the plain and the colored.

Mr. Michaux's person was tall, strongly built, but not corpulent His complexion was fair; he was slightly pock-marked, and possessed prominent features. His light blue eyes had a peculiar expression, which startled me at first His countenance was stern and cold on first approach; but it smoothed off and brightened gradually as he spoke and became more familiar; his utterance, in the beginning somewhat slow and cautious, became rapid and impressive, and his conversation gay and even humorous. His manners were quite simple and unaffected, frank and lively - they were altogether those of an open-hearted country gentleman, in whose presence, young as I was at the time, I could feel neither embarrassment nor shyness.

I do not think that since this interview with Michaux his position and pursuits underwent much change. To the very last day of his life he was fortunate enough to retain his health and remarkable activity of body and mind. The main point of his arboricuitnral experiments was to turn to advantage those lands, called heaths, which, in France alone, do not cover less than two millions of acres, and were considered utterly sterile. Through forty years of experiments performed by him on the large demesnes belonging to the Central Society Of Agriculture and to Mr. Delamarre, he has ascertained that such lands could be improved and rendered prodnctive by the cultivation of certain resinous trees, which succeed well in such soils. Of all the American and European pines with which he has experimented, Michaux gives the preference to the Russian Pine, Pinus sylvestris, which, in bis letter to the President of the American Philosophical Society, above mentioned, he recommends warmly to the particular attention of the agriculturists of the Northern and Middle States of the Union.