ists are a t an end. Rather, we hope that we have made some contribution to identifying the real issues that require attention. I t isimportanttodistinguish salary and tenure data for all women in academe from the data on entry-leuel tenuretrack faculty members. We reported that for women hired within the last 10 vears. there is little discrepancy in salary . or tenure rate: only at PhD-granting institutions are slower tenure and promotion rates for women still observed. Thus. we projected that by the year 2000, little difference would be ohserved for women newly hired into professorial ranks at anv believe that this will be the --" tvnp ~ " -of -~ institution. - - ~ - ~We ~ still ~ ~ ~ case. We did report, however, that of the PhD-granting institutions. there is a low hire rate for women into tenure-track and a high hire rate for women into nontenure track positions. We also noted that discrepancies in salary, rank,and tenure rate persist for women who were hired more than 10 years ago. ACS Statistical Services and the Committee on Professional Training have responded to requests to eather more data in the future on those in nontenure track positions in academe. As we wrote, i t is the number of women who hold doctoral degrees in chemistry that ultimately limits the participation of women in academe. With only a third of them now choosing academic careers, rectification of the cumulative effects of cultural biases and inequities will necessarily take many years. Thus, we urge parents and educators to continue encouraging girls to study science and those who teach undergraduates to involve women in research projects that arouse their interest in pursuing advanced degrees. ~
Paradoxical Statistics To the Editor: Can some reader enlighten me and others on the following paradoxical situation that can and does arise in chemical statistics. Suppose ( A s ) are two distinct variables and observations indicate that thev be linearlv correlated. Therefore. - mieht " upon a coordinate translation, one would expect a linear regression of the forms B = k A o r A =k'B
~
-
Nina M. Roscher The American University Washingttin. DC 20016
Margaret A. Cavanaugh
where k' = llk. I t is known, and has been so demonstrated (I), that the usual linear regressions, performed on the same data base, yield, in general, different results depending on which variable is chosen as the independent one. This implies k' # llk. Moreover, by definition, (A$) are distinct properties and, because there are only two of them, they are, in general, also structurally distinct. I t follows that a function should not exist and a linear regression on (A$) has Lo rational meaning. This leads to paradoxical questions such as: What are the chances of becoming pregnant from smokingcigarettes? This is aquestion that is clearly senseless, but can vield a correlation. 1iis disturbing that with the advent of pocket calculators such procedural problems are given little thought. Literature Clted 1. Spiegei. Murray R. Sfofirlies:Sebsvm Outline Series, 1981:Chspter 13.
H. Brauchll I00 W. University Parkway Baltimwe. MD 21210
Salnt Mary's College Notre Dame. IN 46556
The Dlfilculty of Retrlevlng Useful Information To the Editor: On a Reaction lnvolvlng Oxygen and Metal Sulfides To the Editor: The role of iron(II1) oxide as a catalyst (I) in the production of oxygen by the thermal decomposition of potassium chlorate prompted the idea to use this oxide t o repeat the reactions involving oxygen and the metal sulfides described in an earlier article [1986,63,441]. Oxygen production in the potassium chlorate-iron(II1) oxide combination was very effective even though less spattering and a less exoergic reaction took place than in the potassium chlorate-manganese dioxide combination. The repetition results and the non-repetition results were the same and these should imply using iron(II1) oxide as a catalyst even more in thermal decomposition of potassium chlorate for oxygen production. Literature Clted 1. Nebexall, W.H.;Holtzelaw, H. F.,Jr.; Schmidt, P.C. College ChemistrydoifhQunlitoLiua Annlysis, 5th ed.;
Heath: k g t o n , MA,1976: p 156.
Wllllam D. Hill Jr. North Carolina Cenhai University Durham. NC 27707
448
Journal of Chemical Education
In "A Spectacular Demonstration", J. F. Skinner [1987, 64, 5451 said that the demonstration "does not appear to have been published in this Journal". On the contrary i t was, "TheHydrogen Organ", R. D. Eddy, [1959,36,256], and i t was summarized in Tested Demonstrations, 6th ed. by H. N. AlyeaandF. B. Dutton. Skinner hasprovideds thoroughly useful background to understanding this demonstration, hut his comment points up the difficulty of retrieving useful demonstrations even from a publication as thoroughly iudexed as this Journal. Dean F. Martin CHEWS Center Unlversiv of South Flwida Tamps, FL 33620
Editor's Note: Letters from Lawrence Sverdrup of Western Research Corporation in San Diego, California, end Robert A. Goldenberg, Fort Erie Secondary School, Ontario, also pointed out the earlier publication of this demonstration.
