The president of the faculty of the school of mines, or professor in charge thereof, who shall be appointed by said board of trustees, shall be known as president of the Colorado school of mines. It is lawful for said president to make or have made by any member of the faculty or by students, for residents of Colorado only, assays and analyses of Colorado ores and minerals and to make reports of such results free of charge upon blanks printed for that purpose, which shall, in a conspicuous place, have printed thereon: "The following is the assay or analysis of sample received from .............., and is not to be used in any way for promotion purposes."