DEAR SIR,--I am indebted to you for Mr. Bowditch's very learned mathematical papers, the calculations of which are not for every reader, although their results are readily enough understood. One of these impairs the confidence I had reposed in La Place's demonstration, that the eccentricities of the planets of our system could oscillate only within narrow limits, and therefore could authorize no inference that the system must, by its own laws, come one day to an end. This would have left the question one of infinitude, at both ends of the line of time, clear of physical authority. Mr. Pickering's pamphlet on the pronunciation of the Greek, for which I am indebted to you also, I have read with great pleasure. Early in life, the idea occurred to me that the people now inhabiting the ancient seats of the Greeks and Romans, although their languages in the intermediate ages had suffered great changes, and especially in the declension of their nouns, and in the terminations of their words generally, yet having preserved the body of the word radically the same, so they would preserve more of its pronunciation. That at least it was probable that a pronunciation, handed down by tradition, would retain, as the words themselves do, more of the original than that of any other people whose language has no affinity to that original. For this reason I learnt, and have used the Italian pronunciation of the Latin. But that of the modern Greeks I had no opportunity of learning until I went to Paris. There I became acquainted with two learned Greeks, Count Carberri and Mr. Paradise, and with a lady, a native Greek, the daughter of Baron de Tott, who did not understand the ancient language. Carberri and Paradise spoke it. From these instructors I learnt the modern pronunciation, and in _general_ trusted to its orthodoxy. I say, _in general_, because sound being more fugitive than the written letter, we must, after such a lapse of time, presume in it some degeneracies, as we see there are in the written words. We may not, indeed, be able to put our finger on them confidently, yet neither are they entirely beyond the reach of all indication. For example, in a language so remarkable for the euphony of its sounds, if that euphony is preserved in particular combinations of its letters, by an adherence to the powers ordinarily ascribed to them, and is destroyed by a change of these powers, and the sound of the word thereby rendered harsh, inharmonious, and inidiomatical, here we may presume some degeneracy has taken place. While, therefore, I gave in to the modern pronunciation generally, I have presumed, as an instance of degeneracy, their ascribing the same sound to the six letters, or combinations of letters, ε, ι, υ, ει, οι, υι, to all of which they give the sound of our double _e_ in the word _meet_. This useless equivalence of three vowels and three diphthongs, did not probably exist among the