"Section 1.    The bar examinations and the examinations given by the various boards of examiners of the Government are declared as civil service examinations, and shall, for purpose of appointment of positions in the classified service the duties of which involve knowledge of the respective professions, except positions requiring highly specialized knowledge not covered by the ordinary board examinations, be considered as equivalent to the first grade regular examination given by the Bureau of Civil Service if the profession requires at least four years of study in college, and as equivalent to the second grade regular examination if the profession requires less than four years of college study: Provided, however, That such bar or board examination shall be equivalent to the next lower grade of civil service examination when the person is to be employed in a position other than one requiring his professional knowledge: And provided, further, That if under any law, a person is exempted from the examinations given by the various boards of examiners, and a certificate of registration for or admission to the practice of his profession is issued in his favor by the corresponding board of examiners, he shall be deemed for all legal purposes to have passed the required board examination for the practice of his profession."