216 



Mr. G. King and Dr. A. Newsholme. 



In Tables X and XI the death-rates have been corrected for age 

 distribution, and a single illustration will indicate how important is 

 this correction, and how serious an error may result from its omis- 

 sion. Taking from Tables III and V the total population at risk for 

 all ages, and the total deaths from cancer, and dividing the second 

 by the first for each period of years for England and Ireland respec- 

 tively, we shall have the death-rates from cancer in the form usually 

 presented by the Registrar- General. They are given in the following 

 table, and alongside them are placed the corrected rates from 

 Table X. 



Table D. Comparison of Corrected and Uncorrected Cancer Death- 

 rates. 



It will be observed that by the uncorrecfced figures Ireland stands 

 a little above England for the first two periods, and a little below it 

 for the other three, but that no very great difference appears between 

 the rates for the two countries. The corrected figures, however, 

 show that Ireland stands below England throughout, so that in the 

 first two periods the position of the countries is reversed by the 

 correction, and in the last three periods the difference in favour of 

 Ireland is very great indeed. It is evident that the ordinary method 

 of presenting the statistics exaggerates the rate of cancer in Ireland 

 as compared with England, a result which, as already explained, 

 might have been expected, owing to the age distribution of the 

 populations of the two countries. 



Much light may be thrown on the subject by a careful analysis of 

 Tables X and XI. It is, however, difficult from arrays of figures to 

 ascertain their exact teaching, and it is, therefore, desirable to aid 

 the mind by translating the figures into a graphic form. In Tables X 

 and XI the rates of mortality from cancer are given for five periods 

 of years, and from them the rates may be obtained for each indi- 

 vidual year. If these subdivided results be then plotted out in 

 curves, the forms and directions of the curves will show at a glance, 

 far more conclusively than could the most elaborate examination of 



