APEIL27, 1900.] 



SCIENCE. 



661 



literature, has lessened the frequency and the 

 possibilities of famines, has increased longevity 

 by making life safer and more comfortable. It 

 has extended marvelously the power of pro- 

 duction, and, consequently, of consumption. 

 It has made the world cosmopolitan, upsetting 

 old ideas and old customs. It has lifted strug- 

 gling humanity to a higher plane and has stim- 

 ulated a higher intelligence." 



In agriculture our 45,000 workers are aided 

 by the equivalent, in brain-power, crystallized 

 in machinerjr, of over 300,000 men. Our 

 225,000 workers in cotton manufacture are 

 aided by the equivalent of about three millions, 

 by the multiplication of their productive power 

 by use of their labor-assisting machinery. In 

 flouring mills, 65,000 workers iu the United 

 States are made equal to nearly five millions. 

 In paper-making, 30,000 men become equal to 

 a million and a half. These workers of the 

 United States, four and a half millions of men, 

 with machinery at their finger-ends, turn out a 

 product that it would require nearly forty mil- 

 lions of men to produce by hand. Locomotives, 

 alone give us the equivalent of the working 

 power, if unaided, of three hundred and fifty 

 millions of men. Our own people derive about 

 twice as great advantage from labor-assisting 

 machinery as do European nations ; the popu- 

 lation of the United States being equal in pro- 

 ductive power to 150,000,000 Europeans. Says 

 Mr. Wright : 



"The reflection comes that a labor-saving 

 machine is best defined as a contrivance by 

 which the dead still work. For the motive 

 power of steam is the stored heat of the sun 

 converted into present power. That heat gives 

 force to the present era ; while the intelligence 

 of the inventors of motive power, or of the ma- 

 chines which control it, and their workmen 

 are still working in unconscious iron and con- 

 verting the heat into motion and doing the 

 work of the world." Thus the machine "has 

 practically enabled one generation of men to do 

 the work of four or five generations." 



The deduction of the editor of the Scientific 

 American is that machinery, by raising wages, 

 increasing their purchasing power, also thus 

 lowering costs of all the necessaries of life, has 

 become recognized ' ' not, as the agitator will 



even yet suggest, the enemy of labor, but in 

 every respect its best friend." 



E. H. Thurston. 



Outlines of the Comparative Physiology and Mor- 

 phology of Animals. By Joseph Le Conte. 

 New York, D. Appleton & Co. 1900. Pp. 

 xviii + 492. 



The impression given by the general appear- 

 ance of this book is very favorable ; print, il- 

 lustrations, paper and binding are all good. A 

 rapid turning over of the pages at first confirms 

 this impression for the general plan of the work 

 is most admirable. Function is the basis of the 

 work and structure is described only so far as 

 is necessary for the proper understanding of 

 function. In short it continually reminds one 

 of that admirable volume of a generation ago, 

 the Principles of Zoology which was jsrepared 

 by Agassiz and Gould and which served as the 

 inspiration of many a youth. 



In his treatment Professor Le Conte begins 

 with some general accounts of life, cells and 

 histology and then follows a general account of 

 the organs and functions of animals, classifying 

 them as the animal and the vegetative functions. 

 In the treatment throughout man is made the 

 type and the subject is treated in the descend- 

 ing scale. 



A work built on these lines might be made al- 

 most ideal as a text-book for our schools, but 

 not with our present knowledge. There are 

 too many unknown quantities upon the physi- 

 ological side. Professor Le Conte' s book has also 

 another shortcoming. It contains too many inac- 

 curate statements. On the whole it is better upon 

 the physiological side than where it attempts 

 to deal with morphology, yet here it is far from 

 free from error and ambiguity. Thus the ac- 

 count (p. 5) of the characteristics of plants is 

 true only of the chlorophyl bearing forms; thus, 

 again, the only suggested function of motor 

 nerves is to cause muscular contraction ; thus 

 (p. 65) the electrical organs of a fish are stated 

 to be organs for the conversion of nerve force 

 into electricity just as a muscle is a structure 

 for converting nerve force into mechanical 

 power. On p. 58, along with an erroneous con- 

 ception of the paths of sensory conduction, the 

 ganglion cells of the dorsal roots are placed iu 



