The late William Earl Hidden was a very keen, observing and intelligent collector. His early training as designer for a banknote company—a profession in which he was very proficient—was brought to a close when he was twenty-four years of age, thru lack of proper encouragement on the part of the company, and thru his own restlessness. He preferred to spend his time looking up mineral localities, in mining, in the collecting and selling of coins, etc. Had he remained at his bank-note designing, no doubt he would have attained eminence in that line. He attended the evening chemical lectures at the Cooper Union from 1873 to 1876. We were students together in the chemistry and physics departments of the Cooper Union.