tively inconceivable ignorance of even the
rudiments of science. The author uses such terms, for instance, as 'heat'
in a way that would lead one to infer that he had let the entire wave of
modern thought on the subject of physics sweep past him unperceived. Any
one familiar with the mere elements of this science would show him that
not even the merest dilettante could have made these statements, and they
can only be dismissed as the outcome of rank ignorance."

This and many a similar verdict might be pronounced, and we can picture
our reader, after the perusal of a page or two, laying the book
aside,--smiling or indignant, according to his temperament,--and reflecting
on the singular growths which a perverse tendency of thought may put forth
in our time. So thinking, he will lay this volume aside, with his
collection of similar freaks of the brain. What, however, would the author
say should such opinions come to his knowledge? Would he not, from his
point of view, also set the critic down as incapable of judgment or, at
least, as one who has not chosen to bring his good will to bear in forming
an intelligent opinion? To this the answer is most emphatically--No! In no
sense whatever does the author feel this, for he can easily conceive of
his critic as being not only a highly intelligent man, but also a trained
scientist, and one whose opinions are the result of conscientious thought.
The author of this book is able to enter into the feelings of such a
person and to understand the reasons which have led him to form these
conclusions.

Now, in order to comprehend what the author really means, it is necessary
to do here what generally seems to him to be out of place, but for which
there is urgent cause in the case of this book, namely, to introduce
certain personal data. Of course, nothing will be said in this connection
but what bears upon the author's decision to write this book. What is said
in it could not be justified if it bore merely a personal character. A
book of this kind is bound to proffer views to which any person may
attain, and these views must be presented in such a way as to suggest no
shade of the personal element, that is, as far as such a thing is
possible.

It is therefore not in this sense that the personal note is sounded. It is
only intended to explain how it was possible for the author to understand
the above characterized opinions concerning his presentations, and yet was
able to write this bo