ties are used during wartime by the Army and Navy Medical Supply Depot for the vast amount of microscopic work that is necessary in the Armed Services. Balsam fir Canada is a product of Canada. It represents the exudation of a particular fir tree. It contains about 20 per cent of essential oil and approximately 80 per cent of a quick-drying resin. It becomes very hard upon exposure to air and has a refractive index very near to that of glass. For this reason balsam fir Canada resin in xylol, balsam fir Canada resin, and balsam fir Canada itself are used in tremendous quantities in the manufacture of optical instruments and equipment. In this war, candy for the soldiers, sailors, and other armed forces is indeed a very important item. Essential oils are used for flavoring these candies. Usually, they are of the hard candy type. Candy flavored with oil sweet orange, lemon, or lime requires the presence of a small amount of citric or tartaric acid to bring out its pleasant flavor characteristics. Citric and tartaric acids are not available in the usual quanitities, so manufacturers have resorted to a root beer flavor and others which do not require the presence of these acids. Root beer flavor is made up of a mixture of various essential oils, principally oil sassafras natural and oil sweet birch. Due to the shortage of dry spices, practically all manufacturers of food products have now resorted to the use of spice essential oils such as: oil cloves, pimento, cassia, cinnamon, and nutmegs. It has been found that these spice essential oils can be incorporated in dehydrated foods and in canned products in a more satisfactory manner than was possible with the dry spices. The pickle industry now uses essential oils for flavoring, such as oil dill weed, oil dill seed, and the various spice essential oils almost to the exclusion of dried spices. Because this war is of a global nature with fighting going on in all types of climates and under widely divergent conditions, oil citronella Ceylon, oil citronella replacement number 21, oil pennyroyal American, and some of the other essential oils have been supplied to the armed forces for use as insect repellents. Oil wormseed, for example, was shipped by air to Brazil for treatment of hooldorm. Now that planes make rapid trips from different countries to our country, it has been found necessary to spray the planes inside and out to kill insects that may have been brought from another land. Practically all of the insecticides that are used for this purpose contain small amounts of essential oil mixtures sometimes called perfume oils, to make the odor of the spray more agreeable to human beings. Balsam tolu, a product of South America, is collected by natives in the deep interior of that continent. Uniquely enough, the balsam is shipped to the United States in five-gallon tins which originally contained gasoline and kerosene. Balsam tolu is used by the armed forces for the manufacture of a cough syrup
and for certain other pharmaceutical preparations. Oil turpentine U. S. P. gum spirits, produced from the pine trees of the South, plays an important part for the armed forces. This material is used to make up liniments suitable for humans as well as horses and accompanies the armed forces wherever they go. Fats are scarce and it has been necessary to make soap from the types of fats and oils that would not ordinarily be used for this purpose. Essential oils and essential oil mixtures are used to cover the odor of these low-grade fats and thus make the soap more acceptable to the consumer's use. Many essential oils are not available any longer and will not be brought into this country until after the war. Successful efforts are being made to grow some of these products in the United States, South America, and Central America. The outstanding example of this is oil dill weed. Not so many years ago practically all of this material came from the regions around the Mediterranean Sea. Today all of i t is produced in the United States. Essential oils are used for flavoring tooth pastes, shaving lotions, talcum powders, hair tonics, presaiptions, fly sprays, insecticides, adhesive tapes, ointments, varnishes, paints, coated gum paper, chewing gum, and embalming fluids. Manufacturers of embalming fluids are always trying to make a more acceptable and suitable odor for their product.. In making a suitable essential oil odor for flea powder, the question arises as to whether the dog or the flea has to be pleased. CORRECTION
On p. 154 of the March issue of THISJOURNAL the last sentence in "Modern heat treating practices," the article by Charles A. Pethybridge, should read, "For case depth of 0.040 inch and less. etc." and not "0.40 inch."
NOTES Mr. Elbert C. Weaver, Andover, Massachusetts, attended (as an official representative of the N.E.A. C.T.) the informal meeting of the National Commission of Science Teaching held a t 315 Riverside Drive, New York, on March 19, 1944. The following organizations have named official representatives to the Commission: N. Y. C. Federation of Science Clubs, National Association for Research in Science Teaching, American Nature Study Society, Division of Chemical Education of the American Chemical Society, American Council of Science Teachers, North Central Association of Science and Mathematics Teachers, American Science Teachers Association, Catholic Conference of Science Teachers, Middle States Association of Science Teachers, and the American Association of Physics Teachers. Professor Philip G. Johnson, Cornell University, is acting Chairman of the Commission. The purposes of the Commission have been delineated as follows: 1, to make the influence of science organizations a potent force
through the unification of their efforts; 2, to bring about a national offensive so that the sciences may he given a just and reasonable opportunity to serve the needs of all youth; 3, to study the effects of this war on science teaching and to make recommendations with respect to the more desirable types of pre-induction training; 4, to plan a long-range program for the improvement of science teaching; 5, to assist scienceteacher organizations in reaching science teachers and school administrators; 6, to stimulate widespread and intelligent cooperative action on problems of science teachers. The need for the Commission grew out of the minds of a number of leading science teachers who felt the lack of a plan for science teachers to work together to achieve these aims. It was thought +hat a united effort in one organization of joint sponsorship could accomplish more than many groups working separately. At this informal meeting it was suggested that the time was ripe for a national organization of science teachers to include the following features: 1, sponsor-
ship by both educators' and scientists' groups, probably jointly by the National Education Association and the American Academy for the Advancement of Science; 2, scope broad enough to include the interests of all science teachers; 3, fusion of various groups such as the American Science Teachers Association, the National Commission of Science Teaching, and perhaps others, to achieve an economy of interest; 4, fusion of several journals into one publication hut in no case interference with regional groups nor with specialized journals. Further discussion took place a t the Cleveland meeting of the American Chemical Society on April 3 to 6. Dr. Mary C. McKee of the Chemistry Department of Connecticut College, New London, Connecticut, will he the local representative on the Summer Conference Committee. The Conference will be held from Thursday afternoon, August 24, to Monday afternoon, August 28, 1944, during the summer session of the College a t New London.
