I must make a digression now, to arrange suitable contacts between the preceding parts of my narrative and its concluding chapters. The main object of my narrative has been to describe the rise of idealism in American science, and particularly in physical sciences and the related industries. I witnessed this gradual development; everything I have written so far is an attempt to qualify as a witness whose testimony has competence and weight. But there are many other American scientists whose opinions in this matter have more competence and weight than my opinion has. Why, then, should a scientist who started his career as a Serbian immigrant speak of the idealism in American science, when there are so many native-born American scientists who know more about this subject than I do? Those who have read my narrative so far may answer this question. I shall only point out now that there are certain psychological elements in this question which justify me in the belief that occasionally an immigrant can see things which escape the attention of the native. Seeing is believing; let him speak who has the faith, provided he has a message to deliver. * * * * * A foreign-born citizen of the United States has many occasions to sing praises of the virtues of this country which the native-born citizen has not. Such occasions arise whenever the foreign-born citizen revisits his native land and hears opinions about America which are based upon European prejudice born of ignorance. On these occasions he can, if the spirit moves him, say many things with much more grace than a native American could. The spirit will move him if his naturalization means that he knows America’s traditions and embraces their precepts with sincere enthusiasm. Statements which, coming from a native American, might sound as boasts and bragging, may and often do sound different when they are made by a naturalized American citizen. I have had quite a number of experiences of this kind; one of them deserves mention here.