instruction, now so popular, I found the same superficiality and uncertainty that existed everywhere else. But the more deeply I was impressed with this state of things, and the more fully I became aware of the injurious and trying consequences of the method of teaching followed at the present day, the more earnestly was I impelled to press onward in search of light and clearness in this dim domain.

Convinced that only by the way of scientific investigation the desired end could be reached, I sought the counsel of Prof. Helmholtz, in Heidelberg. This distinguished man was then engaged in a scientific inquiry into the natural laws lying at the basis of musical sounds. Prof. Helmholtz permitted me to take part in his investigations, and at his kind suggestion I attempted by myself, by means of the laryngoscope, to observe the physiological processes that go on in the larynx during the production of different tones. My special thanks are due to him that now, with a more thorough knowledge of the human voice, I can give instruction in singing without the fear of doing any injury. My thanks are due in a like manner to Prof. du Bois-Reymond, in Berlin, who, at a later period, also gave me his friendly help in my studies.

In 1861 I published a part of my investigations in Germany, where they found acknowledgment and favor. That little work is contained in the following pages, together with some account of the discoveries of Professor Helmholtz relating to the human voice, and of their practical application to the education of the voice in singing.

The practical sense of the American people enables them, above all others, to appreciate the worth of every discovery and of every advance. And therefore it is my earnest hope that the publication of these investigations in this country may help to elevate and improve the Art of Singing.