This part of the course ends on April lst, after which date a new sort of work is begun. Each pupil is assigned some substance for study and preparation, a different assignment to each boy: he reads up the literature on his substance, writes a theme, reads this before the class with illustrations, and sometimes with lantern slides. Then hegoes into thelaboratory and makes a considerable quantity of this substance, keeping track of his costs, purity of materials and of product, and the like. Then he reports to the class a second time, showing his product, discussing its purity, cost, yield, etc., and answering questions. He compares his cost with current market prices and shows his loss or profit as the case may be. These assignments include both organic and inorganic substances and when finished are turned into laboratory stock. We have about 2000 pupils in this school, all boys: 315 are taking Chemistry 1 this year and 42 are taking Chemistry 2. A boy may start Chemistry 1 in either thud or fourth year, so if he wants to take two years of chemistry he must foresee this in time to start his Chemistry 1in third year. Pupils in the scientific course are required to do this, their elections being in some other department. Very truly yours, CITYCOLLEGE,
LESLIE H.
INGHAM
B A L T I M OMD. ~.
We have for many years followed a one-year course of seven periods per week on general chemistry with a second-year course of 7 periods per we*& in the qualitative analysis of the common metals. The methods of separation throughout the entire scheme are developed inductively and applied deductively in the determination of metals in a large number of solutions, salts, and alloys. The class-room part of this course consists of a study of principles suggested in these analyses and the commercial processes used in the production of these metals and their chief compounds. This is followed as far as time will permit by the preparation of common inorganic substances based on Arthur A. Blanchard's "Synthetic Inorganic Chemistry." There are two objects in this course (1) a training in careful manipulation and in logical experimentation, (2)through class-room work to broaden and deepen the student's knowledge of chemical principles, their application in the production of the metals used in this qualitative chemistry, and the uses of these metals and their chief compounds. While this course has been successful and more students would take it were there time to do so, I am inclined to the belief that one year of chem-
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istry in a high school is enough either for the student who goes to college or the one who does not, provided he takes other sciences and essential academic subjects. MCKINLEYTECHNICAL H. S., WASHINGTON, D. C.
THE METRIC SYSTEM AND MR. DALE Many of Mr. S. S. Dale's arguments against the metric system' and in criticism of my articleZhave previously been answered by Professor Bingham.' However, Mr. Dale's arguments do not stay answered and he has dusted them offfor us again. As historians, Mr. Dale and I seem to be greatly a t variance. This is due partly to his pisinterpretation of some of my statements and partly to the fact that our sources of information are different. This is often the case in historical questions where we have to depend upon opinion or authority. I did, however, point out that decimalization is the intrinsic property of the Arabic system of enumeration, and there seemed no necessity for Mr. Dale to take the trouble to convince us that the practical use of decimals must have been invented before the time of James Watt! Fortunately the claims for the metric system are not based upon its history but upon its advantages for present-day usage. If the opponents of the metric system would agree to give metric units a fair trial by practical use, I should gladly yield to Mr. Dale on every historical pointeven to the "red blood of the French Revolution." I trust he will not deny that some good may have come out of so much blood. Mr. Dale criticizes the chart of the Metric Association which shows the advance of metric usage by countries because, on this chart, large and small countries are given equal importance. For example, the non-metric British Empire and metric Belgium are given equal values without regard to statistics of area, wealth, and population. The point intended in the chart is that each country represents a definite decision in favor of the metric system and that all but two countries have made this decision. It is not necessarily true that the largest and richest countries are the wisest and most progressive. The inability to distinguish between 1 "Educating the Public in Weights and Measures," Tn~s J a m , 2, 1064-7 (1925). 2 "Educating the Public in the Use of the Metric System," Ibid.. 2, 593-9 (1925). "Xnswering Mr. Dale on the Metric System," I.I d . Eng. Chem.,News Ed., Oct. 20, 1923.
