6 



2 HARMON NORTHROP MORSE— REMSEN [Mbmoirs iv*uxxi; 



no laboratory. We had less than a handful of students. What was to come of it ? I need not 

 go into the story thus suggested except to say that we were absolutely untrammeled and left to 

 work out our own salvation. Morse and I were of one mind as to the object to be attained, 

 and there were no discussions in regard to the methods to be adopted. They were not original, 

 but they had never been tried in this country. There had never been an opportunity. The 

 opportunity that many of us had hoped for, had dreamed of, was furnished by the bounty of 

 Johns Hopkins and the wisdom of his trustees and of President Gilman. 



Morse remained an associate until 1883, when he became an associate professor. In 1892 

 he was promoted to be professor of inorganic and analytical chemistry, and in 1908 he became 

 director of the chemical laboratory. In 1916 he withdrew from active service and became 

 professor emeritus. 



From the beginning of our work in the new university the importance of research was 

 emphasized. That was indeed its most characteristic feature. Morse was as anxious as any 

 of us to take part in this work. For one reason and another it was some time before he got 

 going. To be sure he did show his hand in some small and rather unpromising pieces of work, 

 and I think he became discouraged, but he was faithful to his teaching. Gradually, however, 

 his researches opened up new fields and he began their exploration. This is not the place for a 

 full review of his contributions, and those of his last years so overshadowed all that preceded 

 that a reference to those alone will do substantial justice to his memory. 



In the early nineties he turned his attention seriously to the question of the stability of 

 solutions of potassium permanganate, and in 1896 he published an article on "The reduction 

 of permanganic acid by manganese superoxide," A. J. Hopkins and M. S. Walker appearing as 

 joint authors. Pursuing this subject Morse and H. G. Byers in 1900 published an article "On 

 the cause of the evolution of oxygen when oxidizable gases are absorbed by permanganic acid." 

 The results were such that it became desirable to obtain an aqueous solution of pure perman- 

 ganic acid. It was decided to prepare this by dissolving the heptoxide in water. In an article 

 by Morse and J. C. Olsen that appeared in 1900 occurs the following passage: 



[We] accordingly prepared a quantity of the anhydride by mixing potassium permanganate and concen- 

 trated sulphuric acid in vessels cooled by ice and salt. We soon learned, however, that something more than a 

 low temperature is essential to safety in handling the product; for a minute quantity of the anhydride — certainly 

 less than half a drop — which had been separated from the sulphuric acid, exploded with great violence and with 

 disastrous results to one of us. 1 Some idea of the force of the explosion may be gained from the fact that one of 

 the flying fragments of glass passed entirely through a burette which was mounted in the vicinity, leaving holes 

 over half the diameter of the burette, edges of which were entirely free from cracks. After this experience, we 

 decided to abandon the anhydride as a source of the acid, and to work out, if practicable, an electrolytic method 

 of separating it from its salts. 



The electrolytic method worked very satisfactorily, and led to the further use of this method 

 in the preparation of osmotic membranes. The first results of this investigation are given in 

 an article by Morse and D. W. Horn that appeared in 1901. They say: 



In this connection, it occurred to the authors that if a solution of a copper salt and one of potassium ferro- 

 cyanide are separated by a porous wall which is filled with water, and a current is passed from an electrode in the 

 former to another in the latter solution the copper and the ferrocyanogen ions must meet in the interior of the 

 wall and separate as copper ferrocyanide at all points of meeting, so that in the end there should be built up a 

 continuous membrane well supported on either side by the material of the wall. The results of our experiments 

 in this direction appear to have justified the expectation and to be worthy of a brief preliminary notice. 



This marks the real beginning of the work on osmotic pressure with which the name of 

 Morse will always be associated. But before the cells were available and therefore before any 

 reliable measurements could be made, years of patient, skillful work were still necessary. Diffi- 

 culties that seemed insurmountable frequently arose and necessitated new efforts. It must 

 be said that some of us in the laboratory, including myself, at times lost faith in the ultimate 

 success of the work and were perhaps inclined to advise the use of cells that were not perfect. 

 But Morse went steadily on. He had in mind a practically perfect cell that could be used for 



• To make this story complete it should be added that Morse was the "one of us" here referred to. A piece of glass passed through the tissues 

 of his neck in close proiimity to the jugular vein. His escape from death was almost miraculous. 



