LITTLE BLUE BOOK NO. 452 Edited by E. Haldeman-Julius A Dictionary of Scientific Terms Leo Markun HALDEMAN-JULIUS PUBLICATIONS GIRARD, KANSAS Copyright, 1927 Haldeman-Julius Company PRINTED IN THE UNITED STATES OF AMERICA A DICTIONARY OF SCIENTIFIC TERMS PREFACE Completeness is a virtue which this little Blue Book cannot, in the nature of things, possess. If any reader is disappointed not to find it here, I must respectfully direct his attention to the three ponderous tomes which make up a well-known dictionary of chemistry, to the still larger and more numerous volumes devoted to a dictionary of applied physics, and to other similar works. The sciences are many, and the words which they employ exclusively or in senses peculiar to themselves are exceedingly numerous. Physics, chemistry, and biology contribute the greatest number of words to the present dictionary. A few terms used in other sciences are included, chiefly to show what I believe the proper scope of a dictionary of scientific terms to be. There is a genuine need for a large dictionary, which ought to be of about the same size as Webster’s Collegiate or the Oxford Concise, and which should deal with the vocabularies of economics, anthropology, sociology, and psychology as well as with those of mechanics, geology, astronomy, and all the older sciences. Such a dictionary should be written by specialists in the various fields of knowledge with the aid of a skilled etymologist, and under the supervision of an editor who is not himself a professional scientist. It would be his special task to see that the definitions are intelligible to non-specialists, and to literate laymen in particular. Of course no dictionary can take the place of primers of the sciences. There are a number of excellent ones in this series, some of which I referred to in writing this book. It is in many cases impossible to give adequate explanations in a few words. Besides, the scientific writers themselves frequently quarrel about the true meaning of such a word as _ether_ or _instinct_. I have dealt here with a number of words which are of significance when we try to set the limits of science. _Common sense_, _philosophy_, _theology_, and _superstition_ are examples. The claims of several branches of knowledge to be considered sciences are also taken up. A DICTIONARY OF SCIENTIFIC TERMS _Abasia._ The inability to walk, especially when it is caused by mental disorder. _Abdomen._ The hind part of insects, spiders, etc. The belly, including the nutritive organs. _Aberrant._ Diverging from normal type. _Aberration._ The non-convergence of rays of light to a focus. The apparent displacement of the true position of a heavenly body. _Abiogenesis._ Spontaneous generation.