not an arbitrary line drawn to fit the observed points. It represents the theoretical relation connecting wave-length and voltage given by X = h/mu. This relation is X = 12.2/~"* when X is expressed in Angstrom units and V is in volts. For example, this theoretical relation assigns to electrons of a speed corresponding to 32.5 volts a wave-length of 2.14 A. From the grating space of the nickel lattice we were able to determine that the wave-length of 32.5-volt electrons is 2.15 A. Similarly the grating space in the C-azimuth of our aystal, 1.24 A. was found to correspond t o 97.5-volt electrons. The value of h/mv for 97.5 volts comes out to be exactly 1.24 A. I f all the experimentally determined wave-lengths agreed exactly with the values of h/mv, all of the points in Figure 9 would fall accurately on the line. The departures are none of them greater than can be reasonably accounted for by the uncertainty of the measurements. It i s quite certain that electrons are diffracted by a nickel crystal as if they were waves having a waue-length given by the quotient of Planck's constant and the electrrm momentum, mv. This is, of course, the chief result of our work. Rolled Oats Responsible for Furfural Discovery. Furfural may well became the chemical word familiar to every household of the coming generation, as coal-tar is t o those of the present. This was the prophecy ventured by C. S. Miner of Chicago, before the Institute of Chemistry of the American Chemical Society. And the discovery that this hitherto rare chemical can be made cheaply in commercial quantities is almost an accident, the result of experiments aimed a t an kntirely different objective, be said. I n the preparation of rolled oats, hundreds of t p s of oat hulls are left as a byproduct a t the end of the milling. Little use could be found for them, and they sccumulated around the mills in vast quantities. I n an endeavor t o render them edible. a t least for cattle, they were subjected to various chemical treatments, and one of these experiments resulted in the production of furfural in appreciable amounts. Since then research has followed two lines: t o produce i t as economically as possible, and t o find new uses for it. Furfural is very active chemically, is a solvent of wide application, and possesses many properties tending t o give i t commercial value. It is a t present being used very extensively in the manufacture of synthetic resins and moulding compounds. Recently a light-sensitive furfural resin has been produced which is used in the preparavlates. Because of its germicidal properties and also its fungicidal tion of vrinting .. . . properties, furfural is finding application in the preventing of fermentation in glues and dextrin pastes, as well as in the preparation of disinfectants and deodorizers. Some derivatives of furfural are being used as seed disinfectants and furfural itself is used in the preparation of tree wound dressings. "Research men are constantly working with furfural and its derivatives and undreamed of uses for them are found every day," Mr. Miner said. "The annual crops furnish an almost inexhaustible, relatively cheap supply of raw material for the production of furfural, and as i t is a highly reactive compound capable of functioning as the raw material far a wide range of chemical manufacturing processes, it may well form the basis of a branch of American chemical industry comparable in importance t o the coal-tar i n d u s t j in Germany."-Science Sem'ce ~
