NATURE 



[March 21, 19 18 



the knowledge of this constant it is easy to deduce 

 at once the value of a number of other important 

 magnitudes with equal precision, e.g. the number 

 of molecules in a cubic centimetre of any gas at 

 standard pressure and temperature, and the mass 

 of each of the atoms of matter. At the same 

 time, the accurate evaluation of e throws light on 

 the magn'itude of a number of related quantities. 



While Prof. Millikan's work was in pro- 

 gress, Ehrenhaft examined the charge carried by 

 particles so small that they showed a marked 

 Brownian movement, and concluded that the 

 charge in some of these cases was smaller than 

 the value found by Prof. Millikan, or, in other 

 words, that there existed a charge less than that 

 carried by the negative electron or gaseous ion. 

 This evidence is carefully examined by the author, 

 who concludes that the discrepancies can be 

 readily accounted for by experimental disturb- 

 ances, and that there is no trustworthy evidence 

 of the existence of a sub-electron. 



Later chapters include a discussion of modern 

 views of the structure of the atom and the nature 

 of radiant energy. Very appreciative references 

 are made to the value of Moseley's work, and its 

 great importance in fixing the relation and modes 

 of vibration of the elements is emphasised. The 

 author is a supporter of the nucleus theory of the 

 structure of the atom, and outlines clearly Bohr's 

 contributions to the origin of spectra. 



Prof. Millikan's book is written in a simple, 

 almost popular, style. The argument throughout is 

 well sustained, and the essential points are clearly 

 brought out. Stress is laid on the underlying 

 physical ideas, and thp few calculations required 

 are included in an appendix. We can recommend 

 this volume most strongly both to scientific experts 

 and to the general scientific public as an accurate 

 and at the same time inspiriting account of an 

 important field of scientific inquiry opened up in 

 recent years. E. R. 



A STUDY OF THE JEWISH CHILD. 

 The Jewish Child: Its History, Folklore, Biology, 

 and Sociology. By W. M. Feldman. With 

 introduction by Sir James Crichton-Browne. 

 Pp. xxvi + 453. (London : Bailli^re, Tindall, 

 and Cox, 1917.) Price los. 6d. net. 

 r\R. FELDMAN 'S study of the Jewish child 

 -*--' should be of interest to English readers for 

 at least two reasons. First, because out of a 

 total of twelve million Jews in the world, one-fifth 

 are, at present, living in English-speaking coun- 

 tries — more than two millions in America,, and 

 less than a quarter of a million (240,000, to be 

 exact) in the United Kingdom. The second rea- 

 son is that the British Government, with the coa- 

 sent of the Allies, proposes to use its best en- 

 deavours to establish, under the aegis of the 

 British Government, a national home for the 

 Jewish people in Palestine, where they might be at 

 liberty to develop in accordance with their national 

 aspirations. • 



Dr. Feldman is well qualified to lead us in the 

 NO. 2525, VOL. lOl] 



study of the Jewish child ; for not only is he well 

 acquainted with modern Jewish child-life, havir^ 

 a big practice among the Jews of Whitechapel, 

 but he is also well versed in Jewish literature^ 

 ancient and medieval. His book represents the first 

 attempt to give a comprehensive account of Jewish 

 child-life in all its phases and aspects, and takes 

 us through the whole life-cycle of the Jewish child, 

 including the ante-natal, natal, and post-natal 

 periods. 



The book may be divided roughly into two 

 parts, historical and scientific. The historical 

 part deals with the state of knowledge of child-life 

 among the ancient and medieval Jews. By means 

 of numerous quotations and citations from the 

 Bible, the Talmud, and Rabbinical literature, the 

 author demonstrates, first that the Jews were 

 keenly interested in all the phases of child-life, and 

 secondly that the amount of true knowledge they 

 possessed on this subject was not inconsiderable. 

 For it must be noted that the broad principles of 

 eugenics and hygiene were strictly enforced by the 

 laws of Moses, and repeatedly enjoined by the 

 teachings of the Rabbis as a religious duty. The 

 scientific part, on the other hand, deals with such 

 questions as the physical, biological, and patho- 

 logical characteristics of the modern Jewish child. 



One of the most important chapters in the book 

 is that which discusses the vital statistics of the 

 Jewish child. At a time when the problem of 

 infant mortality looms large in the public eye, it is 

 interesting to note that among Jews the infant 

 mortality is, at all ages of child-life, considerably 

 lower than among the general population, and not 

 only in England, but in all other countries. The 

 chances of surviving the critical first year are also 

 much greater among Jewish infants. Contrary 

 to the popular belief, the Jewish birth-rate is less^ 

 and yet their degree of increase is greater, than 

 that of non-Jews. This is because their infant mor- 

 tality is considerably lower. As Leroy-Beaulieu 

 puts it, the Jews " bring fewer children into the 

 world, but they bring more of them to maturity.'" 

 " This low infantile mortality," Dr. Feldman re- 

 minds us, " is not due to any inherent racial 

 vitality in the Jewish child, but is due to the almost 

 universal prevalence of breast-feeding among 

 Jewesses, to the lesser incidence or almost entire 

 absence of transmissible taints resulting from 

 diseases acquired by the parents in the worship of 

 Venus and Bacchus, and lastly to the great general 

 care bestowed on their children by Jewish parents, 

 who fly to the doctor for almost every infantile 

 ailment." 



The chapter on the system of education among* 

 the Jews proves how highly education was valued 

 by them so far back as 2000 years ago. This zeal 

 for education, both Jewish and secular, is still very 

 marked among the Jewish population of the East 

 End. Among other subjects, the author dis- 

 cusses the effects of first-cousin marriages among 

 the Jews. He also eives us an interesting and 

 lucid account of the recent study of Jewish 

 physiognomy by Dr. Redcliffe Salaman, who came 

 to the conclusion that the Jewish type of face is a 



