A canvass of the men in one department found one hundred per cent. of those teaching general or inorganic chemistry approving the selection of a term for such compounds. This communication seeks the answer that other read-
EDUCATION would ers of the JOURNAL OF CHEMICAL give to the committee's question quoted on page 496. B. CLIFFORDHENDRICKS 315 AVERYL ~ B O R ~ ~ T O R Y LINCOLN, NEBRASKA
THOMAS GRAHAM TO A. W. To the Editor DEARSIR: ).,:A short time ago, while doing some reference work in the library of the chemistry department of Iowa State College, I came across a very interesting letter written
on the back flyleaf of the hound copy of Volumes 1and 2 (1868-1869) of the Berichte der deutschen chenzischen Gesellschft. It was a letter written by Thomas Graham, the noted English pioneer in colloid chemistry, to A. W. von Hofmann, President of the Berlin Chemical Society, on December 28, 1868, shortly before Graham's death, September 16, 1869. This letter is self-explanatory and appears to be of some historical value. . . . . I have been unable to determine the source of this
VON
HOFMANN
hound copy of Volumes 1 and 2 of the Ben'chte. It was acquired by the Iowa State College Library in 1909. There is no record here of where or from whom it was acquired. My theory is that these volumes were obtained from the library of A. W. van Hofmann, who
died on May 5, 1892. Apparently von Hofmann bound this letter with his own copy of Volume 2 of the Berichte since a considerable portion of this volume deals with the life and works of Thomas Graham. The front flyleaf of Volume 2 contains a photograph of Graham. The announcement of Graham's death to the Berlin Chemical Society on October 11,1869, by van Hofmann is given on pages 475 and 476 of this volume, and a review of Gmbm's life and works is given by von Hofmann on pages 753 to 780.
This letter has now been removed from Volume 2 of the Berichte and is kept with the special documents in the Iowa State College Library. The paper had become yellow and somewhat brittle, but i t has been
placed between transparent sheathing, and it will probably last in this manner for a long time. S. I. ARONOVSW AGRICULTURAL BYPRODUCTS LABOMTORY U. S . DEPARTMENT OF AGRICULTURE AMES, IOWA
ETHER PEROXIDES in a free flame; the properties of this substance were identical with those of triacetone peroxide prepared DEARSIR: from acetone and thirty per cent. hydrogen peroxide Recent correspondence has pointed out the explosion in the presence of hydrochloric acid (BAEYERAND hazard in the distillation of ethers containing peroxides VILIGER,Ber., 33,858 (1900)). (DEGERING, J. CHEM.EDUC.,13,494 (1936); MORGAN The isolation of triacetone peroxide from di-isopropyl AND PICKARD, J . SOG.Chem. Ind.,55,421 (1936); WIL- ether, which has stood for some time, is suggestive that LIAMS, Ibid., 55, 580 (1936)). Di-isopropyl ether was the latter type of peroxide as well as diacetone peroxide considered among the most hazardous. are responsible for the explosions d u ~ the g distillation An old sample of di-isopropyl ether was examined of old di-isopropyl ether. M. S. KHARASCH in this laboratory and found to contain a large quantity M. GLADSTONE of a peroxide which was isolated and identified as triacetone peroxide, ( C ~ H B OM.P. ~ ) ~ 98% , This peroxide THEUNIVERSITY OF CHIUW CmUGO, ILLINOIS exploded when rubbed on a clay plate or when heated
To the Editor
"PATENTS FOR ACTS OF NATURE" To the Editor In "Patents for Acts of Nature" appearing in the issue of Science for April 28, 1939, a t page 387, I advance the thesis that novel true chemical compounds, as such, are not entitled to patent protection because they cannot be "inventions," inasmuch as a true "invention" is a specifically human affaircreating or contriving by m a n s o m e thing or some action or series of actions performable upon materials that man can, and does, make or perform-in short, a purely human accomplishment, whereas every true chemical compound is, in itself, solely a creation of nature; and I demonstrate that the decisions of the courts implicitly, if not explicitly, sustain this thesis. This thesis
does not deny patent protection to novel true chemical compounds as products of specific patentable processes, but i t does deny patent protection to novel true chemical compounds apart from the specificpatentable processes utilized to produce them. My purpose in bringing "Patents for Acts of Nature" to the attention of your readers is to elicit from them as chemists criticisms, pm and/or con, but most especially con, of its thesis, for I have in preparation an exhaustive treatment of this thesis and I want to incorporate all such criticisms in this proposed longer paper. Communications sent to me will receive immediate attention. CHARLESE. RUBY 94 HUNTINGTON AVENUE BOSTON, MASSACHUS~S
"A STUDY OF EQUATIONS OF STATE" To the Editor DEARSIR: Attention has been called by Professor Louis J. Bircher of Vanderbilt University to the fact that Getman and Daniels in their "Theoretical Chemistry," (sixth edition, page 14), attribute the equation,
p(o- b) =Rt, to Budde instead of to Clausius aswas done in the article, "A Study of Equations of State." It has been impossible, so far, to check the authority for this statement. Authority for attributing it to Clausius comes from Loeb, "Kinetic Theory of Gases" (second edition, pages 171-2),and from the original paper of van der Waals.
