T o the Editor: Back in 1943 and 1944 I gave my freshmen students

a t Cooper Union a working rule that the electron shells were filled in increasing order of the value (n + 1). This rule, along with the well-known (?) wave pattern definitions of the quantum numbers, made possible a completely mathematical construction of the entire Periodic System (even to the radioactive rare earths since revealed!). The students seemed to appreciate that "number magic."

Meanwhile, I searched everywhere for some published mention of this absurdly simple rule, and finding none, bravely featured it in my 1945 articles. I even added a completely specific modification, "n + 1/(1 + 1)" (pp. 313 (frontispiece scale), 319, 320, 422, and diagram scale on p. 423). Since then this rule rested quietly.and

now that confuse individuals. I see no justification for the term "Avogram." Existing terms answer our purpose.

We have an International Commission on Atomic Weights which provides the relative weights of the various elements. We also have the relative isotopic weights of the many varieties which now exist, though a few are still missing. I do not see why it is necessary to have an "Avogram" in which the relative weights would probably not differ appreciably from those of either the atomic weights or the relative weights of isotopes, un- less a new series of numerical values is adopted. .

unchallenged. Now twice in the same December, 1948, issue, this T O the ~ r l i t , , ~ :

rule is mentioned (Simmons, p. 659; and Carroll and Lehrman, p. 662) without any reference to its colorful Periodic System application of just three years ago. While it may seem immodest of me to mention this, I really think that we will hear a great deal more of this little rule as the years go by, and we might as well date this atomic awakening a t least back to July, 1945.

To the Editor: In your issue of July, 1945 (p. 319), Mr. William J.

Wiswesser announced a rule for the order in which the electron subshells are filled. That announcement pre- ceded that of Yeou Ta in Annales de Physique 1, 93 (1946), and therefore in my communication published in your December, 1948, issue, I should have referred to Wiswesser's rule rather than to Yeou Ta's.

L. M. SIMMONS TEE SCOTS COLLEQE SYDNEY, AUSTRALIA

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May I request that you publish, in your esteemed journal, the following modification of the so-called "Iodoform Reaction" for the detehtion of ethyl alcohol in very dilute sohtions? I have used this method with great success for the last fifteen years in the B.Sc. Laboratory of the T. N. J. College, Bhagalpur.

For carrying out this reaction, about 2 to 3 ml. of diluted alcbhoi are taken in a test, tuhe and an equal volume of decinormal (or stronger). iodine solution is added to it. Then one or two pellets (small pea size) of solid caustic soda, according to the extent of dilution of alcohol, are dropped into the mixture. The color of iodine quickly disappears as the test tuhe is very gently shaken to dissolve the pellets, and gradually the crystals of iodoform appear. With more diluted solu- tions .of alcohol, the crystals appear after a minute or two. With still more diluted alcohol, one or two extra pellets of caustic soda should be added and the shaking continued a little longer, until the pellets have dis- solved. With a little care, this method may also be used with alcohol which has been diluted to more than 50 times. With acetone, the method is successful up to 500 times dilution or more, as has been found by one of my colleagues here.

T o the Editor: The success of the procedure is due to low solubility Regarding the letter on page 113 of the February of iodoform in concentrated caustic soda solutions and

JOURNAL OF CHEMICAL EDUCATION. I sueeest that un- the slow heatinn effect ~roduced bv the eradual solu- ~ ~ ~ ~ ~ uu - less absolutely necessary we refrain from adding new tion of solid caustic soda. This re vents any hydroly- terms to the scientific vocabulary. We have too many sis of iodoform, even in the presence of a concentrated

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