with the substitution of manganese for calcium. It was found that the manganese salts on pyrolysis gave higher yields of ketones than calcium salts and that mixed manganese fonnate and higher manganese carboxylates gave aldehydes. As a result of this survey, I feel that the authors were unjustified in their claim that the literature did not support the statement that carbonyl compounds were formed on pyrolysis of calcium carhoxylates. It is true, however, that the general method is not one to he recommended for classroom use. I hope this information will be of interest to you. PATRICK J. FLANAGAN U N I V E R ~ COLLEGE TY DWLIN,IRELAND
To the Editor:
Often in analytical work it becomes necessary to weigh samples of a volatile liquid accurately. Weight burets are rather inconvenient and too expensive for general student use. Recently, a t the suggestion of Frank R. Russo, a student in our quantitative analysis class (now with Interchemical Company, New York), we have used a glass vial (Kimhle no. 60975 L "Opticlear" vial 4 dram 25.24 X 52 mm) with a tightly fitting polyethylene cap. An ordinary cork borer is used to bore a hole through the cap so that a medicine dropper fits tightly. Liquid may be accurately weighed in this vial and samples may he rapidly taken dropwise. If the density of the liquid is known and the volume of the drops determined, specified weights may be readily taken. Our students have successfully used this device for several semesters to weigh samples of amines into glacial acetic acid for non-aqueous acid-base titrations.
To the Editor: I n utilizing an approach similar to the elegant gas law experiments described by D. A. DAVENPORT, THIS JOURNAL, 39,252 (1962), we have found that the disposable plastic syringes, now available from most medical suppliers, are more satisfactory than glass ones.' They are virtually unbreakable, gas tight, cost only about $0.30 and need no lubricant. We have used them in 'This work was performed under the suspices of the US. Atomic Energy Commission.
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conjunction with inexpensive Bourdon gauges (Marshalltown Mfg. Co., Marshalltown, Iowa) to demonstrate P, V, T relationships. The inlet of the gauge is first covered with a disc of soft rubber held in place by a washer and an open nut screwed onto the threaded inlet. Gas is injected into the gauge from a 20 ml graduated plastic syringe with its needle pushed through the rubber seal. Gauge pressure is read against syringevolume and the latter, V, plotted against 1/P (gauge plus barometric). Such a plot gives a straight line of slope nRT and intercept I/- V,. Vo,the internal volume of the gauge, serves as an "unknown" for the student. I n demonstrating the relations of P and T the syringe is mounted firmly in a heating bath on a ring stand. By clamping the gauge and syringe in place with the syringe piston resting on the bottom of the bath, the volume of gas trapped in the syringe and gauge (about 12 to 17 ml) can be held constant. The temperature of the bath is slowly raised to about 75'C and total pressure plotted against absolute temperature. Such a plot affords a straight line with intercept a t 0°K and slope nR/V. If the student is then given the density of his gas he can derive and verify the value of R. It was found that #10 tin cans made excellent heating baths. They are cheap, unbreakable, and may he heated much more rapidly than beakers. Thus, heating took 100 minutes in a 3-liter Pyrex beaker and only 30 minutes in a #I0 can.
ARGONNE NATIONALLABOEAMRY ARGONNE, ILLINOIS and ST.PROCOP~TTS COLLEGE
To the Editor:
A. B. Garrett's new series, "A Flash of Genius," 39, 287 (1962) makes interesting reading and, with help from readers, can continue for a long time. Maybe i t will last as long as the Horace Walpole hoax, now in its third century. The "Travels and Adventures of Three Princes of Serendib" (not Serendip) has nothing to do with accidental discovery. The unnamed princes simply resolved a series of minor crises by close ohservation and logical deduction in the Sherlock Holmes fashion. Walpole's flippant "serendipity" both distorts the fable and belittles discovery itself. See I ~ H N , T. S., Science, 136,760 (1962).
F. MARSCHNER ROBERT AMERICAN OIL COWPANY WHITINGLABORATORIES WHITING, INDIANA EormR's NOTE: Although the basis on which "serendipity" was established as a term may be questioned, it is a convenient and frequently used label. We are reminded of "organic" chemistry, a term which seldom is abandoned because of its incorrect cannations. The "p" in place of "b" may also be blamed on Walpole or his contemporaries who either were taking liberties with or were trying to transliterate the Sanskrit Sinhaladuipa (Ceylon). See Encyclopaedia Rrilanniea.
