6o THE POPULAR SCIENCE MONTHLY 



"child pox." Eotch reports that during fifteen years no deaths from 

 smallpox occurred in Boston in children who had been vaccinated under 

 five years of age, while during the same time the mortality in the unvac- 

 cinated was 75 per cent. Similar conditions have been noted in other 

 centers. It is hard to realize what overwhelming calamities were once 

 caused by this fearful disease. Smallpox has now been practically 

 stamped out in civilized countries by vaccination, yet it has been esti- 

 mated that 60,000,000 died from this loathsome affection in Europe 

 during the eighteenth century, and multitudes who did not die were 

 permanently scarred and mutilated. The reign of destruction and 

 death accompanying this disease continued until Jenner's great dis- 

 covery in 1796. In Germany, where a compulsory vaccination and re- 

 vaccination law has been enforced, there has not been an epidemic of 

 small-pox for thirty-five years, although adjacent countries, not so pro- 

 tected, have had numbers of epidemics. 



In the present discussion, it is interesting to note that a lower death 

 rate from small-pox has been largely confined to children as they are so 

 generally vaccinated. After the first decade, the protection is apt to 

 wane and revaccination is required for full safety. The last objection 

 to vaccination — the possible induction of other diseases — has now been 

 completely removed by experiments on calves which shows that small- 

 pox virus may be converted into a protective but innocuous vaccine virus 

 by being transmitted through several bovine generations. Calf vac- 

 cination thus provides an adequate amount of virus that is safe because 

 produced under careful scientific oversight of an animal fully protected 

 from any disease or outside contamination. 



While in the above-mentioned diseases the preponderating benefits 

 in treatment have accrued to children, there are others in which the 

 child shares with the adult in the advances derived from animal experi- 

 mentation. 



Malaria 



Malaria, to which children are very susceptible, has been made largely 

 a preventable disease by a study of the mosquito carrier, its breeding 

 places and natural history, and by inoculation experiments on animals 

 and man. It was proven by Italian observers that the mosquito dissem- 

 inates bird malaria in the same manner as in the human subject. The 

 final upshot of these investigations has been that large tracts of hith- 

 erto waste and dangerous land have been rendered safe and productive. 

 A widespread cause of debilitating sickness, and even of death, has thus 

 been removed. In such areas, the saddest sight has been the stunted, 

 anemic children, with enlarged livers and spleens, the evidences of 

 chronic malarial poisoning that can now be obviated by putting modern 

 knowledge into effect. 



