T o the Editor:

stration apparatus described in many textbooks, to demonstrate that the products of combustion of a candle weigh more than the candle. He describes a ...
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Stiek t o t h e Job

The Burning of a Candle

T o the Editor:

T o the Editor:

Congratulations on the editorial in the July issue of the JOURNAL OF CHEMICALEDUCATION. If you have not yet seen it and studied it, I would urge that you look up General Lewis B. Hershey's Occupational Bulletin No. 10, dated June 18, 1942, on Critical Occupations and Scientific and Specialized Personnel. I believe that this could be made the subject of a very cheering editorial and a return to the attack on this problem of students in chemistry and chemical engineering going into the enlisted reserves. It would seem that, after the issuance of this Occupational Bulletin No. 10, there is no excuse for a student in chemistry or chemical engineering doing anything but stick to his own job and do i t the best he can. If he goes into the reserve he is going to be lost to chemistry or chemical engineering, because of the proven fact that the needs of the Army and Navy for chemists and chemical engineers are much smaller than the number of such men they have now. FRANK C. WHITMORE PENNSYLVANIA STATE COLLEGE STATE COLLEGE, PENNSYLVANIA

The author of an article in the March, 1941, number states that he has failed to make work the demonstration apparatus described in many textbooks, to demonstrate that the products of combustion of a candle weigh more than the candle. He describes a fairly elaborate apparatus to replace it. For the past ten years I have kept permanently made up the usual (to me) textbook apparatus. I take it from its shelf once a year, demonstrate i t with monotonous success, and put it back for another year. I should say that I have replaced the S O D A - L ~ (NOT E caustic soda) about once in three years. I append a diagram with dimensions. The apparatus is counterpoised on an ordinary laboratory balance reading to 0.01 g. The lower cork is removed, the filter pump (working gently) attached to the exit tube, the candle lit and replaced. The experiment is allowed to continue for three minutes. The filter pump is disconnected and the candle then goes out. The gain in weight is 0.3 g., i. e., 0.1 g. per min. and I have found this extraordinarily constant