On June 15:
1667 The first human blood transfusion was adminsitered by Dr Jean-Baptiste Denys. The blood was taken from a sheep and transfused to a boy who survived. The fate of the sheep isn’t mentioned.
1844 Charles Goodyear recevied a patent for vulcanization to strengthen rubber.
1966 a bomb explosion in Manchester injured more than 200 people. Police blamed it on the IRA.