P.S., January 29th, 1875.--You will see that by a stupid mistake in the address this letter has just been returned to me. It is by no means worth forwarding, but I cannot bear that you should think me so ungracious and ungrateful as not to have thanked you for your long letter. As I forget whether "Cambridge" is sufficient address, I will send this through Asa Gray. (PLATE: CHARLES LYELL. Engraved by G.I. (J). Stodart from a photograph.) CHAPTER 2.IX. GEOLOGY, 1840-1882. I. Vulcanicity and Earth-movements.--II. Ice-action.--III. The Parallel Roads of Glen Roy.--IV. Coral Reefs, Fossil and Recent.--V. Cleavage and Foliation.--VI. Age of the World.--VII. Geological Action of Earthworms.--VIII. Miscellaneous. 2.IX.I. VULCANICITY AND EARTH-MOVEMENTS, 1840-1881. LETTER 479. TO DAVID MILNE. 12, Upper Gower Street, Thursday [March] 20th [1840]. I much regret that I am unable to give you any information of the kind you desire. You must have misunderstood Mr. Lyell concerning the object of my paper. (479/1. "On the Connexion of certain Volcanic Phenomena, and on the Formation of Mountain-chains and the Effects of Continental Elevations." "Trans. Geol. Soc." Volume V., 1840, pages 601-32 [March 7th, 1838].) It is an account of the shock of February, 1835, in Chile, which is particularly interesting, as it ties most closely together volcanic eruptions and continental elevations. In that paper I notice a very remarkable coincidence in volcanic eruptions in S. America at very distant places. I have also drawn up some short tables showing, as it appears to me, that there are periods of unusually great volcanic activity affecting large portions of S. America. I have no record of any coincidences between shocks there and in Europe. Humboldt, by his table in the "Pers. Narrative" (Volume IV., page 36, English Translation), seems to consider the elevation of Sabrina off the Azores as connected with S. American subterranean activity: this connection appears to be exceedingly vague. I have during the past year seen it stated that a severe shock in the northern parts of S. America coincided with one in Kamstchatka. Believing, then, that such coincidences are purely accidental, I neglected to take a note of the reference; but I believe the statement was somewhere in "L'Institut" for 1839. (479/2. "L'Institut, Journal General des Societes et Travaux Scientifiques de la France et de l'Etranger," Tome VIII. page 412, Paris, 1840. In a note on some earthquakes in the province Maurienne it is stated that they occurred during a change in the weather, and at times when a south wind followed a north wind, etc.) I was myself anxious to see the list of the 1200 shocks alluded to by you, but I have not been able to find out that the list has been published. With respect to any coincidences you may discover between shocks in S. America and Europe, let me venture to suggest to you that it is probably a quite accurate statement that