cliv THE BEGINNINGS OF LIFE. 



accepting to the full all doctrines which inculcate the necessity 

 of diminishing the chances of contagion by every available 

 means, let us, full of hope, diligently seek also for the causes 

 which engender even the most contagious of diseases. Pre- 

 vention of disease is the grand end and aim of medicine ; if, 

 then, we have learned from the sad lessons of experience 

 that scarlet fever and small-pox are virulently contagious dis- 

 eases ; if, even in ninety-nine cases out of a hundred, or even 

 in a still larger ratio, both of these diseases are acquired by 

 contagion, then is it all the more important that we should 

 strive to ascertain what are the invariable and immediately 

 antecedent sets of conditions, or states of system, which 

 suffice actually to engender these maladies. In such cases 

 knowledge and power are most frequently convertible terms. 

 Next to typhus fever, the most fatal of the infective diseases 

 which occur in this country are scarlet fever 1 , small-pox, 

 measles, and hooping-cough. The ravages of typhus in our 

 crowded cities and in our jails have been enormously curtailed 

 not so much because of its diminished spread by contagion, 

 but rather because we have learned what are the causes 

 which engender it, and are therefore better able to prevent 



1 Mr. J. Netten Radcliffe says (Ranking's Abstract,' vol. xli. 1865), 

 ' The Registrar-General's returns of scarlet fever for the whole of England, 

 include two periods of five and sixteen years respectively. The first 

 period extends from 1838 to 1842, and the second from 1847 to 1862 

 inclusive. The total number of deaths registered from the disease in 

 the twenty-one years was 310,720 ; the annual average mortality for the 



whole series of years was 14,796 The history of the progress of 



scarlet fever in the metropolis differs from that of the entire kingdom in 

 this, that it shows a great augmentation of the mortality from the dis- 

 ease in the last quarter of a century. The annual average mortality 

 from the malady in London during the past twenty-six years was 83 per 

 ico,ooo population. The average varied from 32 in 1841 to no less 

 than 174 in 1863. In the quinquennium 1839-43 the annual average 

 was 78 ; in the quinquennium 1844-48 it increased to 88 ; in the quin- 

 quennium 1859-63 it advanced to 115. The death-rate of 1863 (174) 

 was more than double the annual average of the twenty-six years, 

 1838-64.' 



