Francium was discovered by Marguerite Perey in 1939 when she was researching the radioactive decay of actinium-227. The discovery took place at the Curie Institute in Paris. The element takes its name from the country of its discovery â France.
Worldâs Biggest Dog, Worldâs Heaviest Dog. Hercules: The Worldâs Biggest Dog Ever According to Guinness World Records. Hercules was recently awarded the honorable distinction of Worlds Biggest Dog by Guinness World Records. Hercules is an English Mastiff and whas a 38 inch neck and weighs 282 pounds.
The different mastiff breeds have been bred for guarding and for fighting. The two most expensive dog breeds in the world are the Tibetan Mastiff and French Mastiff. A Tibetan Mastiff. The largest Tibetan Mastiffs can stand over 31 inches tall and the breed typically weighs over 140 lbs. The dogs can be black, grey, brown or even, in some rare instances, completely white.