March 31, 1893.] 



SCIENCE. 



179 



the fact that it applies step for step when d is repJaced by A, the 



finite difference symbol, giving the result A log z = vi — , 



z 



with »i independent of z, which is absurd. 



I am not opposed to the method of infinitesimals when prop- 

 erly presented. It is logically only an abbreviation of the method 

 of limits, and I should, for my owq satisfaction, always want to 

 test new results obtained by it, with the method of limits in full. 

 I should be glad to see Professor Bowser revise his book. There 

 are some good things in it. I trust Professor Bowser and the 

 other authors mentioned will take my criticisms in the spirit they 

 are intended. We are all liable to make mistakes, and if I should 

 indulge in book-writing to any extent, there would no doubt be 

 some sins of that kind of my own commission, especially in the 

 subject of infinitesimals. A. S. Hathaway. 



Rose Polytechnic Institute, Terre Haute, lud., March 16, 1893. 



Color of Flowrers. 



Will some of the rea^iers of Science tell me what to use for 

 preserving the color of flowers wlien pressing them? 



Jeanne Neal. 



Saiut Joseph, Mich. 



BOOK-REVIEWS. 



Extinct Monsters. By Rev. H. N. Hutchinson, B.A., F.G.S. 

 New York, D. Appleton & Co. 



This book is, as the author states, a popular account of some of 

 the larger forms of ancient animal life. It is impossible to say 

 too much in favor of the proper kind of popular science. The 

 only argument that scientific research can advance for itself, is 

 that the results of its work will appeal to mankind in general. 

 Scientific investigators must therefore encourage in every possible 

 way all attempts to render science popular and cherish every 

 successful writer in this line. To write popular scientific works 

 is an extremely difficult matter, and there are few in the world 

 who are capable of it. The scientist who is best familiar with the 

 facts is usually either unable to put his facts in a form to be en- 

 joyed by the general reader, or is afraid of losing caste among his 

 friends by doing so. But there is no scientist who does not hail 

 any popular exposition of scientific truth. 



There are two faults into which a writer of popular science is 

 liable to fall. If he is too much of a scientist he becomes too 

 technical, and if he is not enough of a scientist he becomes too 

 discursive and too much inclined to fill his pages with rhetorical 

 flourishes. The present book does not fully avoid either of these 

 two faults. At times the reader is led along through a series of 

 rhetorical exclamation points and feels that the author is en- 

 deavoring to amuse rather than instruct; and at other times he 

 finds technical terms used which he certainly cannot understand 

 in their proper significance. The book aims to reach those unac- 

 quainted with geology, but assumes a knowledge of the succession 

 of geological ages and considerable familiarity with the different 

 strata of rocks. Probably the book would be more instructive if 

 the author had treated his subjects in a little more systematic 

 way, and had not been quite so desirous of introducing popular 

 names on one page to please his non-scientific readers and scien- 

 tific names on the next page to satisfy his sense of scientific con- 

 sistency. 



But. in spite of the trifling in perfections, it must be stated that 

 this book is an emphatic success as a bit of popular writing. The 

 style is easy and interesting. When one takes up the book, he is 

 inclined to read page after page and chapter after chapter without 

 any desire to lay the book down. The author has skilfully in- 

 terspersed striking incidents connected with the discovery of 

 special fossil types in such a way as to add vivacity and life to the 

 whole. 



The most valuable and interesting part of the whole to all must 

 be the figui-es in which the book abounds, drawn by J. Smit. 

 These figures are partly skeletons, and represent our present 

 actual knowledge of the hard parts of the extinct monsters as col- 

 lected in the museums of the world. But the figures which will 



most appeal to the reader are the restorations of these ancient 

 monsters in the flesh. Of course, restorations of extinct monsters 

 have been made many times, and they have been constantly 

 changed as new facts are discovered. The author would not pre- 

 tend that his restorations are final, but it can be claimed fairly, 

 and will be easily admitted, that the restorations, as given in the 

 figures of the present book, are the best that have been made up 

 to the present time, and are certainly nearer the truth in each case 

 than those which have preceded them. 



One is very naturally inclined to feel, after a cursory reading 

 of this book, that the ancient world was filled with nothing but 

 monsters, and perhaps the author would have given a better 

 picture of ancient life if he had interspersed with his njonsters 

 some of the smaller but nu less interesting types of ani mals. But, 

 on the whole, the book is a success as a bit of popidar writing, 

 and can be recommended to all. 



Advnnced Lessons in Human Physiotogi/. By Oliver P. Jenkins, 



Ph.U. 60 cents. 

 Primary Lessons in Human Physiology. By the same author. 



30 cents. Indianapolis, Indiana School Book Co. 

 These two little books are published in the Indiana State series 

 of school text-books, and are designed, one for primary schools and 

 the other for advanced schools. One is glad to see a departure 

 from the plan of teaching simple anatomy and the introduction 

 of a physiological basis of treatment. The physiology of man is 

 studied from the standpoint of general biological truth, and the 

 student may here actually learn something of the laws of life. 



Interpretation of Nature. By Professor Nathaniel S. Shaler. 

 Boston, Houghton, Mifflin & Co. $1.25. 



It is not very common that a person of as much scientific repute 

 as Professor Sbaler of Harvard ventures even indirectly to dis- 

 cuss in print the question of the relations of science to theological 

 problems, and for this reason there is especial interest in the 

 pages of this little book. Professor Shaler, in his preface, tells 

 us that his first contact witli natural science bad the effect of 

 leading him far away from Christianity, but that of late years 

 further insight into the truths of nature have forced him back 

 again towards the grounds from which he had departed. The 

 body of this publication is a discussion of various problems of 

 natural science for the purpose of pointing out how it is that the 

 discoveries of science fail to be in themselves a satisfactory an- 

 swer to man's questions as to the philosophy of nature. The 

 different chapters of the book are not and do not pretend to be 

 arguments upon the subject of the relation of theology and sci- 

 ence. They are rather thoughts upon certain phases of scientific 

 truth and a general inference as to lack of satisfaction which the 

 mind can find if it rests in scientific truths alone. He discusses 

 the general appreciation of nature historically, and then more in 

 detail the general subject of biological evolution, especially in its 

 philosophical aspect. The general conclusion of the whole is as 

 to the lack of a satisfactory foundation for thought in science 

 itself, and the unavoidable feeling which must come to a thought- 

 ful student of some power unknown and lying deeper than the 

 phenomenon which science studies on the surface. Even in re- 

 gard to the scientific aspect of the doctrine of Christianity, Pro- 

 fessor Shaler tells us that "the doctrine of Christ is the summit 

 and crown of the oi'ganic series.'" One cannot but be forcibly 

 reminded of Spencer's grand generalization that scientific fact 

 and religious thought are both truths, and that the final outcome 

 of study is to be a fundamental union of the two. 



This book of Professor Shaler's will be especially interesting to 

 two classes of readers. First to those who have passed through 

 somewhat of this same mental history as that which Professor 

 Shaler points out as his own. This will include a body of scien- 

 tists who had learned to look deeper than the phenomena and to 

 wonder concerning the underlying truths, a class of thinkers 

 which seems to be a growing one at the jiresent time. A second 

 class is the great body of readers who are and always have been 

 in thorough sympathy with religious teachings, and will rejoice 

 to see a scientist of such high standing taking a position so in 

 harmony with the most advanced religious truth. While, on the 



