if(!(sim->elements[thisPart&0xFF].Properties & (TYPE_PART | TYPE_LIQUID | TYPE_GAS)))
m. if(!(sim->elements[thisPart&0xFF].Properties & (TYPE_PART | TYPE_LIQUID | TYPE_GAS | TYPE_SOLID)))
Actually the first thing I tried to do was mix solids. Then I remembered the conversation about the suggested mix tool. If it mixes solids then it will screw up the container that liquids and powders are in. but it should mix liquids and powders.