* * * * * Physiologists as a rule are satisfied with the _observation and exposition_ of phenomena. I have endeavored to _explain_ phenomena. I have gone "behind the returns," as politicians say. I have lifted the mysterious veil, and have obtained glimpses at the process of life. In this manner the voice of the œsophagus was first discovered, which, in logical sequence, has carried me from one discovery to another. Once in the confidence of nature, it freely opened up to me its heart. Comprehending one thing led me on to the comprehension of others. There is no study which is as fascinating as that pursued by introspection. It is self-compensating in the highest degree; all facts thereby evolved being the logical sequence of others previously ascertained. Or, if not always in sequence, they all fit into the same system; everything that has been ascertained being a stone which was waiting to be placed in a certain niche to fulfil a certain purpose in the construction of a harmonious edifice. There was no waste, no material entirely lost; nor will there be at any future time. If similar studies will be pursued by those specially fitted for the purpose, the time may not be far distant when there will not be an atom of our material existence whose meaning and purpose will not be understood. The laws which I claim to have discovered will assist in this accomplishment, as they are of so broad a nature that they may be said to form the substructure to forces and conditions which are at the very root of our existence. I do not pretend to say that in this little book they have been properly treated, nor that I possess the ability, under the best of circumstances, to thus treat them. I have but stated what has come under my observation, and have stated it in as simple and direct a manner as my instinct and my ability have taught me to state it. I have been up on Mount Washington to see the sun rise. It was a beautiful picture; still, there were clouds in the way which here and there obscured my vision, as was to be expected from the unwonted height to which I had risen, and the distant horizon. * * * * * I am not writing for a class, but for the multitude to which I belong, and of which, in its aspirations, its hopes, its sincerity, and its ignorance regarding _specific_ knowledge, I form a part. Hence my thoughts are its thoughts and my language its language. There will be no difficulty, therefore, for _all_ to understand me and to profit by my experience.