“Came the day of the first trial. The propellants were hydrazine and WFNA. We were all gathered around waiting for the balloon to go up, when Dr. Milton Scheer(Uncle Milty) warned, "Hold it - the acid valve is leaking!" "Go ahead - fire anyway!" Paul ordered. I looked around and signaled to my own gang, and we started backing away gently, like so many cats with wet feet.” HumorChemistryJet FuelLiquid Rocket Propellants Book:Ignition!: An informal history of liquid rocket propellants Source: Ignition!: An informal history of liquid rocket propellants