Some of Faraday's earliest experiments, as was incidentally mentioned in an earlier part of this little book, were in connection with chlorine, etc., and then on the making of glass for optical purposes; and it was not, indeed, until he had been at the Institution for about eighteen years that he really entered with any degree of success into his electrical research. Here it is of interest to note a remark which he once made in this connection to the effect that it requires twenty years of work to make a _man_ in physical science, the whole of the previous period being one of _infancy_. Once, however, he had reached this scientific manhood his work was done with remarkable rapidity; he would, once on the track, so to speak, of a discovery, mature it in a space of time so short as to be nothing less than marvellous; and one after another of his "experimental researches" were carried out, completed, described, and the resultant paper submitted to the Royal Society with a rapidity, and at the same time with an accuracy which has never been equalled. He was asked once what was the secret of his success, and answered that the whole secret might be told in three words, they were these "Work--Finish--Publish." Perhaps the centre word is the one on which Faraday would himself have lain most stress--he was always careful to finish everything before he announced it, which makes his almost unexceptional accuracy, considering the rapidity with which he worked, even more remarkable. It is, however, not inaccurate to say that the results which he definitely announced, were never found to be wrong; further developments have of course taken place, but the result of a research as announced by him was never found to be untrue, and has never had to be put aside. He had said, in the early part of his scientific career, "the thing that I am proudest of is that I have never been found to be wrong." And after the death of his friend, Professor A. de la Rive wrote, "I do not think that Faraday has once been caught in a mistake; so precise and conscientious was his mode of experimenting and observing." Dr. Gladstone commenting upon this says, "The extreme rarity of his mistakes, notwithstanding the immense amount of his published researches, is one of those marvels which can be appreciated only by those who are in the habit of describing what they have seen in the mist-land that lies beyond the boundaries of previous knowledge."