# Popular Science Monthly/Volume 41/July 1892/Correspondence

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GENESIS OF THE DIAMOND.
Editor Popular Science Monthly:
SIR: An excellent notice of Prof. A. E. Foote's paper on Diamonds in Meteorites has newly been forwarded to me, and, as it has apparently aroused no little interest in the general public as well as in scientific circles, may I take the liberty of calling attention to the following facts through the pages of The Popular Science Monthly, to which I have for some years past been a subscriber?
In September, 1886, my husband, the late Prof. H. Carvill Lewis, read before the Birmingham meeting of the British Association for the Advancement of Science a paper on A Diamantiferous Peridotite and the Genesis of the Diamond, a small specimen of which he had recently discovered, in situ, in a piece of the peridotite rock underlying the tenacious "blue clay" of the Kimberley mines. He further stated that this "blue clay" was found upon subsequent analysis to be merely the same peridotite rock in a high state of decomposition. The process of freeing the diamonds from the "blue clay," in which they are scattered about like plums in a pudding, is so well known that it need not be dwelt upon.
The peridotite in question is an altered lava, filling the neck of an ancient volcano, which burst its way through a rich deposit of carbonaceous shales. Numberless fragments of this shale, of varying size, were found scattered throughout the peridotite, and Prof. Lewis held that it was the pure carbon from these, which, liberated by the intense heat, and crystallizing slowly out under enormous pressure, had formed the diamonds.
In September, 1887, my husband delivered another address at the Manchester meeting of the British Association for the Advancement of Science, entitled The Matrix of the Diamond, in which he described in full the chemical changes and metamorphoses which the peridotite and its constituents had undergone in passing into the "blue clay." An abstract of this paper was distributed among the geologists present, and was afterward published in the Report of the Association for 1887.
At the close of this paper Prof. Lewis remarked that "if his hypothesis concerning the origin of diamonds was correct, they would certainly be found in meteorites"; but it was not until December of the same year (1887) that he received, through the courtesy of Mr. George Frederick Kunz, of New York, a small fragment of meteoric ore, in the larger portion of which two Russian geologists had newly reported the finding of several minute diamonds. Mr. Kunz found thirteen diamonds, I believe, in his share of the meteorite, and my husband found three; but in both cases all were microscopic. This discovery was soon after announced at the Academy of Natural Sciences in Philadelphia, and a short notice of it was published with the title Diamonds in Meteorites.
To Prof. A. E. Foote, therefore, belongs the honor of finding the first diamonds in American meteorites, and not of discovering that abstract possibility or its first realization.
The manuscript for a comprehensive article on The Origin and Matrix of the Diamond, embodying Prof. Carvill Lewis's Birmingham and Manchester addresses, and the subsequent investigations made by him as to the origin of that gem in the southeastern portion of the United States, is now in the hands of Prof. G. H. Williams, of the Johns Hopkins University, and will, it is hoped, soon be ready for the press.
In view of the foregoing statements, it seems open to question whether the position of the meteoric fragments on the side of an old volcanic crater was not an accidental one, which at all events calls for further investigation before those outside the charmed circle of scientific workers are willing to accept so remarkable a hypothesis as to the origin of our terrestrial diamonds.
* I am, with respect,
* Faithfully yours,Julia F. Lewis.
* Heidelberg, January 29, 1892.
MORE ABOUT THE PENIKESE SCHOOL.
Editor Popular Science Monthly:
President Jordan's interesting article on Agassiz at Penikese forms a valuable contribution to the history of marine laboratories in this country, in giving a list, unfortunately incomplete, of those in attendance at the school during its first session. Might it not be possible to complete the list for both years during which the school was in existence? Such a list would form a valuable appendix to the interesting account of the school given by Mrs. Agassiz in her Life and Letters of Louis Agassiz.
President Jordan does not mention in his article the fact that the laboratory building no longer exists. It was destroyed by fire during last summer. A week before its destruction I visited Penikese with a small party from the Marine Biological Laboratory of Wood's Holl, Mass., and had the pleasure of meeting the present owner of the island, Mr. G. S. Horner, of New Bedford, who kindly gave us permission to carry away for the ​Marine Biological Laboratory anything we might find of interest or of use. We took advantage of this kind permission to detach from the walls the inscriptions which decorated the laboratory, and to which President Jordan refers. They were written on heavy paper and were in perfect preservation; they will hereafter adorn the walls of the linear descendant of the Penikese school the—Marine Biological Laboratory.
The inscriptions were not written upon the blackboard, as President Jordan states, on the authority of Prof. Eigenmann. This was occupied by some notes and drawings apparently used in illustration of a lecture on the vertebrata, said, I know not on what authority, to have been delivered by Prof. Wilder. The inscriptions themselves are not quite correctly quoted by President Jordan. They are as follows:
"Study Nature, not books." "Learn to say, I do not know." "A laboratory is to me a sanctuary, and I would have nothing done therein unworthy of the great Creator."
I quote these from memory, and am not quite sure as to the completeness of the second one, though what I have given contains the gist of it. It is advice which all young teachers, for whom it was primarily intended, should conscientiously heed.
* Yours respectfully,
* J. Playfair McMurrich.
* University of Cincinnati, April 7, 1892.
FLOWERING HABIT OF THE AMERICAN ALOE.
Editor Popular Science Monthly.
Sir: In Grant Allen's very readable paper in the May issue—A Desert Fruit—mention is made of the American aloe (Agave americana) in a way to mislead as to its flowering habit. Permit me to say that the plant in question does not, as the writer says, "flower . . . once in some fifteen years or so"; it flowers once only, and then dies. In this city it is somewhat the exception for a summer to pass without one or more specimens of the agave throwing up an immense flower-stalk—not a spike but a panicle—to the height of twenty-five feet or more, with large clusters of flowers on the ends of its two-to six-foot branching pedicels; but, after the development of the flowers and ripening of the fruit, nothing remains of the previous tall rosette of fleshy leaves but a lot of withered and empty skins. And, by the way, the house-leek (Sempervivum tectorum), which takes several years to flower—five or six in these parts—has the same trick of dying as soon as it completes the process. It is doubtless on account of the habit which both these plants have, of multiplying by suckers or stolons, that many have overlooked their monocarpous nature, and have supposed that the new plants standing around were the same as flowered fifteen years ago.
* George Pyburn.
* Sacramento, Cal., May 1, 1892.
[We are glad to have the above particulars about the habit of the aloe, but we do not find in Mr. Allen's casual words any assertion that the same plant flowers more than once. Editor.]
A CORRECTION.
Editor Popular Science Monthly:
Sir: On page 137 of your May number you inadvertently do a great injustice to Mr. Nicola Tesla, by styling him "the able lieutenant of Mr. Edison."
Mr. Tesla is an independent investigator, whose path has been the development of the alternating current, while Mr. Edison has followed the course of the direct current. I venture to suggest a note of correction.
* Yours faithfully,
* Charles Paine.
* Century Club, New York, April 23, 1892.