88 
Although, like the other zymotic diseases, it kills the 
greatest number under five years of age, it retains its 
virulence to a much longer period than the other com- 
plaints. 28,000 males and 27,000 females are carried off 
by it from ages 5 to 10; from 10 to 15, 5,300 males and 
6,000 females ; but up to the age of 20 its number of fatal 
attacks in five years of life still reaches 1,500 and 1,600, 
and amongst females it continues to kill over 1,000 persons 
in the decade of life 25 to 35. 
In relation to the lesser undulations of scarlet fever, we may 
also note the fact that this disease kills its largest number of 
victims between the ages 2 and 3. 
I might at this point take my leave of the subject of 
epidemic cycles, but I should like also to bring before you 
one or two considerations suggested by the tables before 
us bearing upon the question of the possibility of abolishing 
altogether or mitigating the virulence of these complaints. 
Sir Thomas Watson believes that he is not too sanguine 
in trusting that the abolition of zymotic disease may be 
looked for in the next generation, or at least by his grand- 
children.^ 
And if it were possible to stamp out of the world 
every vestige of the contagion of any one disease, we 
might perhaps hope never to see it again amongst us. It 
would certainly need something like a universal deluge to 
accomplish this, but we may grant that after such a 
thorough annihilation it would take many cons of ages 
before the same disease could be evolved from the harmless 
bacterium or the common septic ferment. 
I fear, however, that something far short of this would 
be the result of our interference, and the questions 
naturally arise, whether by keeping a disease at bay for a 
number of years, we may not be laying up a store of sus- 
ceptible material for it to feed upon in time to come, and 
* Abolition of Zymotic Disease, Kegan, Paul & Co., p. 55, 
