Finding instruments of gaming in suspected houses to be evidence that they are common gaming houses.

When any instruments of gaming are found in any house entered or searched under section 6 or about the persons of any of those who are found therein, it shall be evidence, until the contrary is proved, that such house is used as a common gaming house and that the persons found therein were present there for the purpose of gaming although no gaming or playing was actually seen by the police officer.