14 GENEKAL DEATH-KATE FOR ALL AGES, ETC. 



may be a fairly reliable comparative index of tlie health 

 and sanitary condition from year to year ; while, as regards 

 longer periods, or widely separated localities, comparisons by 

 the indication of a general death-rate are often utterly 

 fallacious or misleading. 



Much pi-ejudice exists in some minds against the use of 

 figures. " Figures can prove anything," is a current popular 

 phrase. 



But even words and phrases, as such, are more easily 

 twisted to wrong uses than figures. Yet we do not despair 

 of arriving at correct conclusions by the aid of facts and 

 figures, where due care, thorough investigation, and logical 

 methods are employed. As a rule it is not so much that the 

 results of computed figures are falsa, as that careless and 

 false interpretations are put upon them. Lord Derby, while 

 presiding over the statistical section in 1865, happily 

 illustrated some of the mistakes of this kind, by the state- 

 ment that erroneous interpretations are taken from 

 death-rate totals where abnormal causes are not 

 taken into account ; for example, " a year of pestilence, 

 not only by its effect on the mortality of the year 

 of its occurrence, but by its clearing away feeble lives, 

 and so lightening the death-rate in years immediately 

 consequent." But, as observed by the President of Section f 

 of the British Association at Birmingham, in 18&6, "There 

 is less to be feared from errors arising out of this source, if we 

 lay to heart the warning uttered by Mr. Goschen on a recent 

 occasion. 'Beware of totals' ; — and if we recognise more fully 

 than we are usually apt to do that a table of figures, even if it 

 be absolutely correct as a statement of facts, is merely raw 

 material, not a finished product. The misfortune is that it 

 is only too frequently treated as the latter." 



Wow tables of totals indicating the death-rates per year of 

 different countries are too commonly treated as finished pro- 

 ducts, whereas I shall in the following remarks endeavour to 

 demonstrate that they are raw materials, so far as deductions 

 relating to comparative health and sanitary condition are 

 concerned. 



With this object in view I shall address myself to illustrate 

 the disturbing effect of the dominant influences already 

 indicated upon the total death-rates in different years and in 

 different places. 



The DisTTJfiBiisrG Effect of Vaeying Peoportions op 

 Persons Living at Various Age GtRoitps. 



To fully comprehend the effect of disturbance from this 

 source we must know in a general way the widely differing 

 proportions which each age group of living persons yield to 



