Professor Wilhelm Ostwald of the University of Leipzig delivered the annual Ingersoll lecture last evening on the subject, "Individuality and Immortality," before an audience which completely filled the New Lecture Hall.

Professor Ostwald opened his lecture by citing the results of scientific investigations, intended to show the inadequacy of man's scientific knowledge. We have the atomic theory that all matter is composed of infinitely minute parts, which keep their individuality unchanged under all circumstances. But scientists have recently shown that radium, an element, appears to change to helium, an entirely different element. This shows that the atomic theory is a mere hypothesis, and that the changeless atoms may be proved actually subject to change, if indeed they exist at all. Scientific predictions, then, may be said to be valuable only for a limited time, until disproved; no predictions for infinite time may be reasonably made.

The immortality of man then cannot be proved by scientific or other reasoning. The fundamental proposition has always been, "Man is Mortal." Man, to be sure, changes continually during his lifetime, and it is natural to believe that the mental and physical changes continue after death. There may then be an infinite continuity of change in mankind.

From an ethical standpoint, however, immortality seems necessary. Man's earthly career is full of experiences which should be adjusted and atoned for in a future life. But this, too, is but a hypothesis.