144 



NATURE 



[April 25, 1918 



include lines of equal annual change in blue. The 

 extreme values of the annual change in D are 

 met with on the Canadian border on the Atlantic 

 coast, where westerly declination has an annual 

 increase of 6', and in the S.W. in Texas and Cali- 

 fornia, where easterly declination has an annual 

 increase of 3'. Inclination is increasing as much 

 as 7' a year in the extreme south of Florida, 

 whereas in the extreme north, on both the Atlantic 

 and Pacific shores, it shows an annual fall of i'. 

 H is falling throughout the whole of the United 

 States, the annual decrease varying from 10 y in 

 the extreme north to 120 y in the extreme south. 

 The volume contains a great mass of magnetic 

 information in a convenient form. 



C. Chree. 



Directions for a Practical Course in Chemical 

 Physiology. By Prof. W. Cramer. Third 

 edition. Pp. viii+119. (London: Longmans, 

 Green, and Co., 191 7.) Price 35. net. 

 "The text of this edition is (apart from a few 

 verbal alterations) identical with that of the second 

 edition. The changes in the external appearance 

 of the book have been made with the object of 

 keeping the price as far as possible at its former 

 level." So runs the preface, and that being so, 

 any extended notice of this book is unnecessary. 

 The second edition was fully reviewed in 

 Nature for March 25, 191 5, and we then took 

 occasion to point out what we conceived to be its 

 defects. These defects still remain, but, in spite 

 of them, the work has been a success, seeing that 

 a new edition has been necessary after so short an 

 interval. . 



LETTERS TO THE EDITOR. 

 [The Editor does not hold himself responsible for 

 opinions expressed by his correspondents. Neithei 

 can he undertake to return, or to correspond with 

 the writers of, rejected manuscripts intended for 

 this or any other part of Nature. No notice is 

 taken of anonymous communications.] 



Reconstruction Problems and the Duty of Science. 



It is sufficiently obvious that the problems of recon- 

 struction following the war will tax the intelligence 

 and good will of mankind to the utmost. It is also 

 certain that mistakes made during this period will 

 have more serious consequences than similar errors in 

 a period of less social plasticity. By the same token, 

 wise moves will produce greater and more permanent 

 good. Never before, perhaps, has the obligation to 

 choose between good and evil been quite so insistent, 

 or the danger of a wrong choice quite so perilous. 



Already we observe several groups of people prepar- 

 ing to deal with this situation. Their methods are 

 diverse, and their aims more or less conflicting. Upton 

 Sinclair sends us the first number of a new periodical, 

 devoted to social justice. Yesterday I attended a 

 meeting in which college students were invited to 

 consider the ethics of Jesus as a foundation for the 

 new democracy. The speaker spent some time" in ex- 

 plaining to us that the movement, which is a national 

 one, was neither pacifist nor pro-German. Business 

 men, we read in the papers, are inviting the Germans 

 to consider the conditions under which it will be pos- 

 sible to resume commercial relations. All these move- 

 NO. 2530, VOL. LOl] 



ments, and others^ invite public discussion, and are- 

 beneficial to that extent at least. Underlying the 

 Christian and Socialist propaganda is the entirely 

 right feeling that mankind must agree on some system 

 of ethics, some basic philosophy, which will make for 

 co-operation and human welfare. It is possible that 

 there is more than one such system which would fairly 

 serve our purpose ; but it is certain that we must, in 

 the main, agree. The very existence of democracy 

 implies some such agreement, and its failures result 

 from the partial lack of it. 



So far, I think scientific men can reasonably, indeed 

 enthusiastically, go with the religious and radical 

 groups. We are all seeking an absolutely neces- 

 sary basis for conduct. Yet at this point,, 

 where we seem unanimous, grave possibilities 

 of conflict arise. The scientific man is obliged 

 to ask : What will be the consequences of the doctrines 

 we propose to adopt, and how will they harmonise ^ 

 with natural law? There was a time when it was 

 generally agreed that illness was due to evil spirits^- 

 and in a certain sense the facts were as postulated. 

 Yet the total ignorance of the nature of those 

 "spirits," of bacteria, left man in a very defenceless, 

 position. Nature penalised him, and she always does, 

 for his ignorance, not asking whether he "ought" to 

 have known. So it must always be, and mere good 

 intentions or pious inotives, without wisdom, avail us ' 

 nothing. They may avail less than nothing if they 

 create an impression that our problems have been met,- 

 when they have only been evaded. This is clearly 

 seen by the ablest representatives of most movements, 

 but not so clearly by a large portion of the rank and 

 file. It is because it is so easy to allow emotion to 

 crowd out intellect, and then to lead it to waste its 

 energies in uninformed sentimentalism, that un- 

 patriotic motives have sometimes been ascribed to 

 those whose love of their country and their fellows was 

 actually keener than ordinary. Such injustice is 

 naturally resented ; but it remains a fact that there are 

 many who for various reasons are particularly in- 

 terested in preventing the great volume of hope and 

 good will from turning the wheels of reform. To 

 such all ineffective efforts afl'ord "aid and comfort." 



While the scientific fraternity, thus confronted with 

 a perplexing situation, is making up its mind how to 

 act, what may be considered a perfect manifesto on 

 its behalf has come from an unexpected source. The 

 New Republic of February i6 prints the report on 

 reconstruction by the Sub-committee of the British 

 Labour Party. The concluding passage of that report 

 reads as follows : — 



"The Labour Party is far from assuming that it 

 possesses a key to open all locks, or that any policy 

 which it can formulate will solve all the problems that 

 beset us. But we deem it important to ourselves, as 

 well as to those who may, on one hand, wish to join 

 the party, or, on the other, to take up arms against 

 it, to make quite clear and definite our aim and 

 purpose. The Labour Party wants that aim and pur- 

 pose, as set forth in the preceding pages, with all its 

 might. It calls for more warmth in politics, for much 

 less apathetic acquiescence in the miseries that exist, 

 for none of the cynicism that saps the life of leisure. 

 On the other hand, the Labour Party has no belief in 

 any of the problems of the world being solved by good 

 will alone. Good will without knowledge is warmth 

 without light. Especially in all the complexities of 

 politics, in the still undeveloped science of society, the 

 Labour Party stands for increased study, for the scien- 

 tific investigation of each succeeding problem, for the 

 deliberate organisation of research, and for a much 

 more rapid dissemination among the whole people of 

 all the science that exists. And it is perhaps specially 

 the Labour Party that has the duty of placing this 



