010 PROCEEDINGS OF THE AMERICAN ACADEMY. 



(We) accordingly prepared a quantity of the anhydride by mixing 

 potassium permanganate and concentrated 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 army dride — 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 ferrocyanide 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 sup- 

 ported 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, skilful work were still necessary. 

 Difficulties that seemed insurmountable frequently arose and necessi- 

 tated 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 



1 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 proximity to the jugular vein. His escape from death was 

 almost miraculous. 



