"No doubt the Legislature realized the extreme danger of persons being subjected to ignominious and serious punishment which the circumstances disclosed by the evidence might not warrant, and therefore endeavoured, by the advice of a preliminary secret investigation, to render the risk of such a result less likely. But in reality what has happened is that a member of the Executive has been furnished with the power to say with regard to offences, the punishment of which has already been provided for and vested in the Judiciary, that the latter shall no longer exercise their discretion in that respect, but in some instances, if there is a conviction, shall award not less than the minimum penalty although that penalty may be considered, having regard to the facts, to be oppressive."