xanthate is formed in the initial stage of the coagulation and resists decomposition by acid much more than does sodium cellulose xanthate.so that the effect is much the same as would be encountered in using a weaker coagulating bath. From what has been said it can be s& that the effect-of increasing the NaOH content of the viscose is also much the same as using a more'dilute spinning bath. a, : Rayon made by the bucket process is reeled directly from th$"'cakeW while rayon is reeled from the bobbins in the latter process. ~h..either case it is given a wash in an alkaline bath and bleached if desired. The qualities which the rayon manufacturer watches and controls are tenacity, elasticity, luster, softness, and dye affinity. Nearly every one of the numerous variable factors which enter into, the production of 'viscose and rayon affect these properties with more or less intensity. To produce uniform rayon, day after day, requires years of experience and it can be readily appreciated, therefore, why it took so many years of practical experimentation to realize the commercial exploitation of the viscose process. The problems which still beset the industry fall into three general classes. First, improvement in the strength and elasticity of the rayon particularly by overcoming the peculiar property of rayon which causes it to weaken when wet. Secondly, the recovery of by-products or waste products such as caustic soda, viscose, spinning bath, etc., and lastly a simplification of methods which will result in cutting the cost of production. The most promising place to accomplish this seems to be in the elimination of some of the steps between the spinning machine and the bleaching of the rayon. When these .things are accomplished viscose rayon may well become the most important ,and useful of all textile fibers. Mud Roads a Chemical Problem, Says Highway Board Chairman. In the early days, when anjautogot stuck in the mud of a country road, the cry was "get a horse." Now i t is "get a &mist." The greatest challenge by the motorized world to the modem chemist that has not yet been answered is the challenge of the clay road, declared Charles M. Upham, chairman of the Highway Research Board of the National Research Council, speaking before the American Chemical Society. Clay. like everything else, will respond t o r The chemist must somehow . aet i t to do three chemical treatment. the s ~ e a k e said. things. He must treat i t so that it will drain instead of absorbing water and turning into due. He must cure i t of its Dresent disturbinp:habit of shrinkinr and swelliw according to the amount of water it bas taken up. He must increase its ability to bear loads when moist, and improve its workability by road machinery. The chemist who can do this will simply revolutionize road construction. A further contribution which chemists may make to highway improvement is in the consistency of asphalt; preventing i t from becoming exceedingly hard in winter and soft asputty in summer.-Science Service ..
