If a devise of realty be upon a condition subsequent which is impossible of performance or which is illegal as being malum prohibitum, it is generally held that the condition is void, but the devise is free and single. In this respect the law pertaining to legacies upon condition materially agrees with that upon devises of realty. But perhaps one of the most unusual distinctions drawn in the law of property is that which is drawn between an illegal or an impossible condition precedent to a legacy of personalty and an illegal or an impossible condition precedent to a devise of realty. With respect to legacies out of personal estate the civil law, which in this respect has been adopted by courts of equity, differs from the common law in its treatment of conditions precedent, the rule of the civil law being that where a condition precedent is originally impossible or is made so by the act or default of the testator or is illegal as involving malum prohibitum, the bequest is absolute just as if the condition had been subsequent. If it be a devise of realty, however, if the condition precedent is void, the devise is void.