In the observations of the meteoric shower of November 13, 1897, at Harvard College Observatory, one of the meteors appeared, according to the calculations, at the height of 406 miles, and disappeared at the height of 43 miles, and at a distance of 196 miles. Another appeared at a height of 182 miles and disappeared at a height of 48 miles, and a distance of 74 miles. The first meteor was red or orange, or, to Prof. W.H. Pickering, the color of a sodium flame, and the other white. Both penetrated the atmosphere to about the same depth, and both were clearly Leonids. These facts go to show, Professor Pickering thinks, that the difference in color noted is not due to a mere grazing of our atmosphere in some cases, and a correspondingly low temperature, but to an actual difference in the chemical composition of the individual meteors. Correspondence. THE FOUNDATION OF SOCIOLOGY. _Editor Popular Science Monthly_: SIR: May I be permitted a word of comment upon your editorial entitled A Borrowed Foundation, published in the December number of the Popular Science Monthly? Whatever my readers and reviewers may have claimed for me, I myself have never claimed to be the discoverer of "the consciousness of kind." Not only Mr. Spencer, as he and you have shown; not only Hegel, as Professor Caldwell has shown; but also nearly every philosophical writer and psychologist from Plato and Aristotle down to the present time has more or less clearly recognized the phenomenon of "the consciousness of kind," although I do not know that any one but myself has called it by just this phrase. The only claim, then, that I put forward for my own work is that, in a somewhat systematic way, I have attempted to use the consciousness of kind as the postulate of sociology and to interpret more special social phenomena by means of it. In other words, I have used it as a "foundation"; and I am not aware that any other writer on sociology has ever done so. Mr. Spencer, I feel quite sure, makes no such claim for himself. The passage which he and you have quoted is taken from the Principles of Psychology; it is not repeated in the Principles of Sociology, where, if it had been regarded by Mr. Spencer as a "foundation," it should have been put forward as the major premise of social theory. Passing over the consciousness of kind, Mr. Spencer has chosen to build his system of sociology in part upon other psychological inductions, in part upon a biological analogy. The tables of the Descriptive Sociology are arranged in accordance with the organic conception, and nine and one half chapters of the Inductions of Sociology in the first volume of the Principles of Sociology are formulated in terms of it. Throughout the remaining parts of the Principles, however, sociological phenomena are explained in terms of two closely correlated generalizations that are