August 18, 1905.] 



SCIENCE. 



203 



medicine is to be the ultimate product of 

 the scientific studies of to-day; no one can 

 question that it is a far higher and more 

 desirable type than curative medicine that 

 now generally seeks to remedy the ills be- 

 gotten through ignorance. The loss to the 

 world by preventable disease is enormous; 

 it includes many of the wise and the good, 

 of the best products of human evolution 

 during past centuries, for no selective ac- 

 tion determines that the worse element 

 shall be wiped out. In truth, the delicate 

 nervous balance of the highly developed 

 human organism seems to be more easily 

 disturbed by the attacks of disease than the 

 grosser clay in which all energy has gone 

 to physical development. To stop this loss 

 is the greatest problem of the future in 

 medicine. And the very first step in this 

 problem is the positive determination of 

 causes of disease, and of the means by 

 which they are transmitted and multiplied. 

 Without this knowledge rational prophy- 

 laxis is impossible; before it and the results 

 of associated investigations of purely scien- 

 tific character, quackery must yield as the 

 night before the day, schools and theories 

 will disappear and medicine will take its 

 rightful place among the sciences. 



Henry B. Ward. 



UlS'IVEKSITY OF NEBRASKA. 



SCIENTIFIC BOOKS. 



The Dynamics of Particles and of Rigid, 

 Elastic and Fluid Bodies. By A. G. 

 Webster. Teubner & Co. 1904. 

 The training of the physicist and that of the 

 engineer are subjects which one can hardly 

 refrain from discussing whenever a new vol- 

 ume designed to furnish some part of the 

 necessary equipment for either appears on the 

 scene. The one which is the subject of this 

 review raises the question in a much more 

 definite way than anything which has ap- 

 peared for some time past. Most of the books 

 hitherto published are either mathematical 

 treatises on special departments of physics, or 



are physical text-books in which mathematics 

 are avoided as far as possible. Professor 

 Webster has attempted, as we shall see later 

 on, to combine the two points of view, some- 

 what on the lines of Thomson and Tait's 

 ' Natural Philosophy,' but better adapted than 

 that work for the class-room. 



The latter part of the nineteenth century 

 has seen a far-reaching change passing over 

 those subjects which deal directly with the 

 interactions of particles of matter. Much 

 careful experimental work has been done and 

 laws and principles have been formulated with 

 such accuracy that the time of the all-round 

 physicist has now to be spent as much at the 

 desk as in the laboratory. In spite of this 

 change, the training of the student is still 

 largely devoted to experimental work and the 

 accuraulation of facts. But few students 

 realize that the phenoraena can nearly all be 

 brought together as the effects of the opera- 

 tion of a few simple laws. They spend so 

 much time and labor in mere manipulation 

 that the end is quite lost sight of in the means. 

 As a matter of fact, many of the earlier ex- 

 periments are made with highly specialized 

 forms of apparatus and could be quite easily 

 replaced by illustrations to be obtained from 

 the machinery which has become an essential 

 part of the daily life in all civilized com- 

 munities. A great saving of time, to be better 

 employed in other directions, might be made 

 by thus laying on a foundation which already 

 exists, and the training would be directed 

 towards the principles and the way in which 

 the laws are manifested rather than to the 

 mere effects themselves. 



There is, of course, a difficulty which is 

 always present in the mind of every teacher 

 — that of retaining the interest and holding 

 the attention of the student. Comparatively 

 few of the latter take an interest in the meth- 

 ods, chiefly mathematical, by which the phe- 

 nomena are dedixced from the general laws, 

 and these few frequently neglect the physical 

 side entirely. And yet it is only by a com- 

 bination of theory and experiment that the 

 best results can be obtained. It is useful for 

 a mathematician to have a knowledge of 

 physics, but it is necessary for a physicist 



