In these cases, the transition from the solid to the gaseous state requires an intermediate liquid state. The pressure referred to is the partial pressure of the substance, not the total (e.g. atmospheric) pressure of the entire system.
Botulism is a rare but serious paralytic disease caused by a bacterial toxin usually produced by the bacterium Clostridium botulinum. There are four generally recognized naturally-occurring types; foodborne, wound, infant, and, rarely, adult intestinal colonization. Iatrogenic and inhalational botulism may also occur.
Botulism is caused by a toxin that affects nerves, and in that sense it is not an infectious disease. The botulism toxin is produced by the bacteria Clostridium botulinum, and is one of the deadliest known toxins. There are 7 different types of botulism toxin labeled A through F. Types C and E are most important in wild birds. While this toxin can also affect humans it is not a zoonotic disease.