NATURE 



665 



THURSDAY, FEBRUARY 18, 191: 



VITAL STATISTICS. 

 Vital Statistics Explained: Some Practical Sug- 

 gestions. (The Chadwick Library.) By J. Burn. 

 Pp. X+140. (London: Constable and Co., 

 Ltd., 1914.J Price 45. net. 



IN a preface to this work Sir \\'illiam Collins, 

 as chairman of the Chadwick Trust, explains 

 that the volume is based upon a course of lectures 

 delivered at Liverpool, under the auspices of that 

 trust. Mr. Burn pays a high compliment to the 

 present Registrar General on the improvements 

 introduced by him into the annual reports of his 

 department, and says that it is now for the first 

 time "possible to discuss and analyse the enor- 

 mous mass of statistics in a coherent and intelli- 

 gent manner." 



The author deals first with the Census as an 

 index to the development of national life. A 

 comparison of the twelfth census, taken in 191 1. 

 with the first, taken in 1801, shows a wonderful 

 advance. Mr. Burn thinks that nearly all the 

 information that can be relied upon is now col- 

 lected. He deprecates further elaboration. 

 "Merely to ask an extra question on the census 

 paper does not ensure a correct answer being 

 given. " 



The leading facts that are shown by the Census 

 returns and the reports of the Registrar General 

 are : (i) a steady decline in the marriage rate 

 during the last thirty years ; {2) a steady increase 

 in the mean age at marriage for both sexes ; (3) a 

 reduction in the birth-rate, both as regards legiti- 

 mate and illegitimate births ; (4) a reduction in the 

 infantile death rate. While these observations are 

 closely related, they point to a number of contri- 

 buting causes. 



The success which has attended the measures 

 that have been taken of late years for sanitary 

 improvement is shown by the statistics of death 

 from various diseases. Small-pox is practically 

 non-existent. Phthisis and tuberculosis -have 

 decreased by more than 50 per cent, during the 

 sixty years since 185 1. On the other hand, th^ 

 deaths from cancer have greatly increased. All 

 these statements have to be qualified by the possi- 

 bility of differences of definition in successive 

 records. 



After a brief chapter on the preparation of mor- 

 tality tables, in which he suggests that in addition 

 to the national tables, municipal and occupational 

 tables should be prepared, Mr. Burn proceeds to 

 show how such tables may be put to practical use 

 by medical men and other persons, and the light 

 they might throw upon causes of death and uf)on 

 NO. 2364, VOL. 94] 



I the prevention of disease. For this purpose he 

 j has examined the rates of mortality of the indus- 

 trial branch of the Prudential Assurance Society, 

 of which he is actuary, and as these are derived 

 from twenty million policies, he claims that they 

 fairly represent the p>opulation of the United King-- 

 dom, a claim which may at any rate be supported 

 if limited to the industrial classes. He arrives at 

 the satisfactory result that there is a steady and 

 continuous improvement going on in the vitality 

 of the country. 



The proper method of graduating a mortality 

 table so that the crude results of the enumeration 

 may be smoothed into a symmetrical curve without 

 destroying the trend of the facts, has exercised 

 the minds of actuaries for some time. The late 

 Mr. Woolhouse, Dr. Sprague, Mr. George King, 

 and others have learnedly discussed it, and the 

 method now generally adopted is that which the 

 German actuaries call by the fanciful name of 

 "osculatory interjxjlation." In an appendix to his 

 volume, Mr. Burn gives a description of this 

 method, so lucid and so simple that any person 

 might employ it without having a knowledge of 

 the mathematical principles upon which it is based. 

 He has certainly the gift of clear exposition, and 

 his little book is calculated to be useful to many 

 persons to whom actuarial science has not hitherto 

 offered any attraction. 



TECHNICAL METHODS OF CHEMICAL 

 ANALYSIS. 



(i) Technical Methods of Chemical Analysis. 



Edited by Dr. G. Lunge and Collaborators; 



English translation edited by Dr. C. A. Keane 



and Collaborators. Vol. iii, part i, pp. xxxi + 



538. Vol. iii, part ii, pp. xv+539 — 1125. 



(London : Gurney and Jackson, 1914-) Two 



volumes. Price 3/. 35. net. 

 (2) Technical Gas-Analysis. By Dr. Lunge. 



Pp. XV + 407. (London : Gurney and Jackson, 



191 4.) Price 15s. net. 

 (i) "TT^HE two sections now issued of volume iii. 

 1 of this imp)ortant work complete the 

 English edition of Dr. Lunge's great monograph 

 published in German in 1910-11. The English 

 edition, however, differs in certain material re- 

 spects from that on which it is based, inasmuch 

 as certain German processes are inapplicable, 

 from the very nature of the case, to British pro- 

 cedure, and it is unlikely, owing to special con- 

 ditions, that they will ever become applicable. 

 Hence particular sections of the work have had to 

 be entirely re-written by British experts from the 

 British point of view, and to this extent these 

 may lay claim to be original productions. .\t the 



C C 



