Scientific Publications. 



SUICIDE : An Essay in Comparative Moral Statistics. By Hknkt Mobselli, Pro- 

 fessor of Psychological Medicine in Royal University, Turin. 12mo, Cloth, $1.T 5. 

 " Suicide" is a scientific inquiry, on the basis of the statistical method, into the laws 

 of suicidal phenomena. Dealing with the subject as a branch of social science, it con- 

 siders the increase of suicide in different countries, and the comparison of nations, 

 races, and periods in its manifestation. The influences of age, sex, constitution, cli- 

 mate, season, occupation, religion, prevailing ideas, the elements of character, and the 

 ^tendencies of civilization, are comprehensively analyzed in their bearing upon the pro- 

 pensity to self-destruction. Professor Morselli is an eminent European authority on 

 f his subject. It is accompanied by colored maps illustrating pictorially the results of 

 statistical inquiries. 



VOLCANOES : "What they Are and -what they Teach. By J. W. Jrnn>, 



Professor of Geology in the Koyal School of Mines (Loudon). With Ninety-six 

 Illustrations. 12mo. Cloth, $2.00. 



" In no field has modern research been more fruitful than in that of which Professor 

 Judd gives a popular account in the present volume. The great lines of dynamical, 

 geological, and meteorological inquiry converge upon the grand problem of the interior 

 constitution of the earth, and the vast influence of subterranean agencies. . . . Kis 

 book is very far from being a mere dry description of volcanoes and their eruptions ; it 

 is rather a presentation of the terrestrial facts and laws with which volcanic phenomena 

 are associated."— Popular Science Monthly. 



" The volume before us is one of the pleasantest science manuals we have read for 

 some time." — Athenaeum. 



" Mr. Judd's summary is so full and so concise that it is almost impossible to give 

 a fair idea in a short review." — Pall Mall Gazette. 



THE SUN. By C. A. Yottng, Ph. D., LL. D., Professor of Astronomy in the College 

 of New Jersey. With numerous Illustrations. 12mo. Cloth, $2.00. 



" Professor Young is an authority on ' The Sun, 1 and writes from intimate knowl- 

 edge. He has studied that great luminary all his life, invented and improved instru- 

 ments for observing it, gone to all quarters of the world in search of tbe best places 

 and opportunities to watch it, and has contributed important discoveries that have 

 extended our knowledge of it. 



" It would take a cyclopaedia to represent all that has been done toward clearing up 

 the solar mysteries. Professor Young has summarized the information, and presented 

 it in a form completely available for general readers. There is no rhetoric in his book ; 

 he trusts the grandeur of his theme to kindle interest and impress the feelings. His 

 statements are plain, direct, clear, and condensed, though ample enough for his purpose, 

 and the substance of what is generally wanted will be found accurately given In his 

 pages."— Popular Science Monthly. 



ILXUSIONS : A Psychological Study. By James Sullv, author of" Sensa- 

 tion and Intuition," etc. 12mo. Cloth, $1.50. 



This volume takes a wide survey of the field of error, embracing In its view not only 

 the illusions commonly regarded as of the nature of mental aberrations or hallucina- 

 tions, but also other illusions arising from that capacity for error which belongs essen- 

 tially to rational human nature. The author has endeavored to keep to a strictly scien- 

 tific treatment— that is to say, the description and classification of acknowledged errors, 

 and the exposition of them by a reference to their psychical and physical conditions. 



" This is not a technical work, but one of wide popular interest, in the principles and 

 results of which every one is concerned. The illusions of perception of the senses and 

 of dreams are first considered, and then the author passes to the illusions of introspec- 

 tion, errors of insight, illusions of memory, and illusions of belief. The work is a note- 

 worthy contribution to the original progress of thought, and may b3 relied upon as 

 representing the present state of knowledge on the important subject to which it ia 

 devoted." — Popular Science Monthly. 



D. APPLETON & CO., Publishers, 



1. 3, and 5 Bond Street, New York. 





