In the year 1851, whilst resident in Frankfort, Reis had become a member of the Physical Society of that city. This Society, which still flourishes, then held, and still continues to hold, its meetings in the Senckenburg Museum. Lectures in Chemistry and Physics are delivered by resident professors in regular courses every week throughout the winter, under the auspices of this Society; and every Saturday evening is devoted to the exposition of recent discoveries or inventions in the world of physical science, astronomy, etc. The most active members of this Society during the time of Reis’s connection with it were the late Professor Böttger, Professor Abbe (now of Jena), and Dr. Oppel, all of whom contributed many valuable original memoirs to the _Jahresberichte_, or Annual Reports, published by the Society. Amongst its corresponding and honorary members it counted the names of all the best scientific men of Germany, and also the names of Professor Faraday, Professor Sturgeon, and Sir Charles Wheatstone. Doubtless the discussion of scientific questions at this Society greatly influenced young Reis. He remained for three years a member, but dropped his connexion for a time on leaving Frankfort. He subsequently rejoined the Society in the session of 1860-61, remaining a member until 1867, when he finally resigned. In the winter of 1854-5 we find him most zealously busied with preparations for carrying out his decision to become a teacher. In 1855, he went through his year of military service at Cassel. Returning to Frankfort, he worked away with his customary and marvellous energy, attended lectures on mathematics and the sciences, worked in the laboratory, and studied books on Pedagogy. “Thus prepared, I set my mind on going to Heidelberg in order to put the finishing touch to my education as teacher. I wanted to settle down in Frankfort in this capacity, and undertake instruction in mathematics and science in the various schools. Then in the spring of 1858, I visited my former master, Hofrath Garnier, in whom I had ever found a fatherly friend. When I disclosed to him my intentions and prospects, he offered me a post in his Institute. Partly gratitude and attachment, and partly the ardent desire to make myself right quickly useful, induced me to accept the proffered post.” In the autumn of the year 1858 he returned to Friedrichsdorf, and in September 1859 he married and founded his peaceful home. Until Easter, 1859, he had but few lessons to give; that he utilised every moment of his spare time most conscientiously in earnest activity and sound progress is nothing more than was to be expected from what has been said above.