2078
JOURNAL OF CHEMICAL EDUCATION
Ocroe~n,1931
One or two graded lists had the comment that the set of questions submitted was not a good chemistry test. Quite a number of the instructors grading these papers asked why ten instead of nine parts could not have been used in question 7, leading an investigator to infer that the examination should be made principally for the ease of the examiner. One questions as to whether it would not be better to have two grades-Pass or Fail. Such an estimation would be as accurate as the difference of onetenth of one per cent given in one of the distribution tables. Literature Cited (I)
STARCH, Science, 38, 630 (1913); School & Society, 2, 242 (1915)
Soil on Mountain Tops More Acid than in Valleys. The higher the sourer, seems to be the rule regarding soil reactions. Confirming by researches in the richest forest region in eastern North America the observations of other investigators in various parts of the world, Dr. Stanley A. Cain of Butler University has collected a considerable series of data from the Great Smoky Mountains region in Tennessee and North Carolina, which is to he developed as the greatest of the U. S. National Parks in the East. Starting with a moderate degree of acidity in the valleys. Dr. Cain found that the soil became more and more sour as he climbed the mountains, reaching the summits and the highest acid concentrations a t the same time. The soil reaction was correlated with different types of vegetation: beech and oak-chestnut forests in the lowlands, laurel "slicks" and other heath types, together with pine woods on the middle slopes, and a t the higher elevations thick growths of spruce trees standing in a deep carpet of sphagnum moss. The most acid soil was found beneath the "heath balds" that crown some of the mountains. Many factors conspire to make acid soil in the Great Smokies region. The underlying rocks are geologically very old, of types that weather into non-alkaline soil. There is a great deal of rain and low evaporation rates, which tends to keep the ground wet all the time. The gmwth of dense vegetation is favored by a mild climate, yet the temperature is low enough so that fallen leaves and dead moss decay very slowly. All these factors tend t o have a cumulative effect, producing a highly developed, beautiful but botanically very peculiar, type of vegetation.-Science Service Magnetism Reveals DBerences in Steel. Magnetism will detect differences in hardness of otherwise similar b a n of steel, it was revealed in a report made by Haakon Styri of Philadelphia to a recent meeting of the American Society for Testing Materials. Steel bars that test magnetically the same before heat treatment will test magnetically the same afterward, Mr. Styri said, provided no differences in hardness or impact strength are brought about during the heating and quenching processes. Mr. Styri's method of testing is to place the steel bars in a magnetic field and note whether the steel would make a good core for an electromagnet. Former methods of testing uniformity in steel hardness, according to the report, have required mechanical means which involve partial destruction of the steel, whereas the testing of the steel's magnetic properties does not have this disadvantage.-Science Scrvice
