There are some criminal offenses the state courts may take jurisdiction of in the exercise of the general police power though punishable under the laws of the federal government, such, for instance, as counterfeiting.27 And where these courts have concurrent jurisdiction, the tribunal which first gets the case will hold it to the exclusion of the other until its duty is fully performed and the jurisdiction evoked is exhausted.28 The rule is, that so long as the federal government has not declared an act to be an offense against its laws, the states may make the act an offense under the state laws. But when congress undertakes to legislate and covers the whole subject, the jurisdiction of the state courts thereafter is at an end.29