I think he is referring to the holocaust or the camps. It could symbolize dark times in his life or night as it is.
All of the countries were having a battle of who could build the biggest bombs, guns, tanks, weapons, technology, etc. which created tension between rival countries. everyone was afraid of the next country being too powerful. Hope it makes sense :-)
They concluded that animal magnetism was fake and that Mesmer<span> was a fraud and his practice had no scientific value. They also found out that although there was belief that he discovered a new fluid, there was no evidence of this and was mostly a part of his imagination. Mesmer was exiled because of this and spent the remainder of his life in Switzerland.</span>
