The fertilized egg cell of a mouse contains 40 chromosomes
This invention was a commercial failure. Edison resolved that in the future he would only invent things that he was certain the public would want. ... This gave Edison the money he needed to set up his first small laboratory and manufacturing facility in Newark, New Jersey in 1871.
found at: https://www.nps.gov/edis/learn/historyculture/edison-biography.htm
