This substance was invented by Dr. Felix Hoenikker as part of the Manhattan Project as a way of helping U.S. Marines deal with mud. This substance melts at 45.8 degrees Celsius, and is relatively safe provided it does not come into contact with water below its melting point, as it can act as a seed to induce crystallization of any water it is in contact with. This substance is used by President Papa Monzano to commit suicide, and is let loose into the oceans when an air force jet crashes into the presidential palace, spilling Mozano's body into the ocean. Identify this substance, critical to the plot of a 1963 Kurt Vonnegut novel.
Ice-9