Be it known that we, Carl Bosch and Wilhelm Meiser, citizens of Germany, residing at Ludwigshafen-on-the-Rhine, Germany, have invented new and useful Improvements in Processes of Manufacturing Urea (for which I have made application in Germany, Aug. 9, 1916; in Austria, July 14, 1917; and in Hungary, July 21, 1917), of which the following is a specification.