Rankine's equation is an entirely empirical development made to fit Regnault's data for carbon dioxide, rather than an attempt to allow for the attractive forces between the molecules, as was implied in the historical discussion. Him ("Theorie mecanique de la chaleur," second edition, Volume I, page 195 (1865)) gives the equation, (. p 7.) (V - b) = Rt, where r is the sum of the internal actions (internil and b is the sum of the volumes of the molecules, This is of historical interest since i t precedes the equation of van der Wads. The reduced equation of Dieteric should read
+
The equation of Shaha and Basu was not obtained from the original paper and was incomplete as given. The reduced form of their equation should read. =
with
~
-
ZT
JI -
c
~
2B 3S243
=
- 2B V
/ ~V In
~
0.3161.
This equation is not suitable for values of V much less than one, since for V = 0.6322, P becomes infinity. GEORGEWOOLSEY Los ANOELESCITYC o ~ ~ s o e Los ANOELES,CALIFORNIA
LECTURE DEMONSTRATION EXPERIMENTS IN GENERAL CHEMISTRY To TEACHERSOF GENERAL CHEMISTRY: Many of your best lecture demonstrations are those which are original with you. That certainly holds true for most of us teaching General Chemistry. But unfortunately we don't know, and therefore can't use, those favorite demonstrations of our colleagues. To help remedy that, I intend to write, for the JOURNAL OF CHEMICAL EDUCATION, a series of articles under the title, "Newer Lecture Experiments in General Chemistry." This letter, therefore, is a plea for help. Will you please contribute exact directions for performing one or a half-dozen of your "pet" lecture demonstrationsthose, of course, which are not mentioned in the literature on Lecture Experiments? A rough or elaborate sketch of the apparatus should he appended.
I intend to arrange the experiments by subject matter, editing where necessary. Every experiment accepted for publication will carry the name of the contributor as well as the name of his institution. I know how busy teachers of freshmen are, hut I honestly believe that the time taken to look through your experiment file and to write up the experiments for this purpose will be repaid many times by the ideas which you will get from the other contributors. Needless to say, the success of this plan must depend almost entirely upon the contributors themselves. Your cooperation will be appreciated. SAULB. ARENSON U,vE,
CINCINNATI
CINCINNATI, OHIO
THE HIGH-SCHOOL COURSE IN CHEMISTRY To the Editor DEARSIR: Mr. Glasoe's article, "The Present High-School Course in Chemistq-A Paradox" [J. CHEM.EDUC., 15, 364-7 (1938)l on high-school courses in chemistry follows the usual line of attack. One would think that the distinguished Board which lately made a study of such a course and published it in one of the JOURNALS of 1936 [J. CHEM.EDUC.,13, 175-9 (1936)l was entirely unfortunate in its conclusions. There is altogether too much bunk being spread around about objectives, preparing for life, motivating for this, that, and the other occupation in life, which, of course, no one really knows a t his high-school age. We are merely trying to project the results of our maturity into the minds of youth and deceiving ourselves into thinking that we have discovered what is wrong with everything. As a matter of fact, the course as compiled by the Board is workable, is an attempt to have the students who are still childra, by the way, get, as early as possible, certain fundamental facts, principles, and cer-
tain technical efficiency in the laboratory. Preparation for life? Certainly; learning the scientific method of getting your data, marshaling your facts and drawing conclusions from these and these only-would that some of our political leaders were chemists! Preparation for college? Well, ask the colleges how our students rate who are using the course mentioned, modified to meet local conditions. But we do not prate about the pot of gold a t the end of the rainbow! Then Mr. Glasoe does not seem to be in touch with some of the latest developments in college chemistry courses, especially in the East. For instance, he might write to Brown University, and he would be obliged to deny his accusation about freshmen repeating the high-school course. Then, too, pupiIs from our school, for example, have been admitted to a sophomore course after proving their qualifications by an examination on the facts, principles, and problems of chemistry -not how to make a pie or prevent an epidemic. J. HERBERTWARD CLASSICAL HIGXSCHOOL PROVIDENCE, RHODE ISLAND
