After the very minute and elaborate paper by Arago, to say nothing of the summary in ‘Silliman’s Journal,’ with the detailed statement just published by Lieutenant Maury, it will not be supposed, of course, that in offering a few hurried remarks in reference to Von Kempelen’s discovery, I have any design to look at the subject in a scientific point of view. My object is simply, in the first place, to say a few words of Von Kempelen himself (with whom, some years ago, I had the honor of a slight personal acquaintance), since every thing which concerns him must necessarily, at this moment, be of interest; and, in the second place, to look in a general way, and speculatively, at the results of the discovery. It may be as well, however, to premise the cursory observations which I have to offer, by denying, very decidedly, what seems to be a general impression (gleaned, as usual in a case of this kind, from the newspapers), viz.: that this discovery, astounding as it unquestionably is, is unanticipated. By reference to the ‘Diary of Sir Humphrey Davy’ (Cottle and Munroe, London, pp. 150), it will be seen at pp. 53 and 82, that this illustrious chemist had not only conceived the idea now in question, but had actually made no inconsiderable progress, experimentally, in the very identical analysis now so triumphantly brought to an issue by Von Kempelen, who although he makes not the slightest allusion to it, is, without doubt (I say it unhesitatingly, and can prove it, if required), indebted to the ‘Diary’ for at least the first hint of his own undertaking.