THE LATE EPIDEMIC OF SMALLPOX. 563 



Unvaccinated but yet 'children of the vaccinated' — is any degree 

 of immunity conferred by inheritance? However difficult of exact 

 demonstration, the affirmative must be accepted not merely as a logical 

 sequence of the experiments in the laboratory to which reference 

 has been made, but by certain clinical phenomena of striking impor- 

 tance. For example, it is well known that among some of the immi- 

 grants touching our shores for the first time, who come from countries 

 where the mosquito is not found, notably from English homes, the 

 ravages produced in midsummer, when women and children especially 

 are lodged in cheap boarding-houses, with windows unprotected by 

 screens, the results of the attacks of the American insect upon their 

 exposed skins are of a grade of severity unparalleled among natives of 

 our soil. Generations of Americans have succeeded in establishing a 

 partial immunity by the mere succession of these accidents in a long 

 series of summers ; so that while they may, and actually do, suffer from 

 mosquito bites, the effects are far milder and without any proportion 

 to those experienced by the immigrant. A striking illustration of this 

 fact is recorded in the history of the Eevolutionary War, when in the 

 midst of their first summer on this soil the mercenary troops from 

 Hesse-Darmstadt and Hesse-Cassel were so savagely attacked on their 

 march from Trenton that whole platoons of troops were unable to dis- 

 tinguish objects through their swollen eye-lids, and were thus rendered 

 wholly unfit for duty. Looking at the obverse of this proposition, every 

 student of public hygiene is aware of the fact that truly formidable 

 ravages of smallpox occur in epidemics attacking virgin populations, 

 as, for example, islanders long unvisited by Europeans, where neither 

 the individuals themselves nor their ancestors for generations have en- 

 joyed the immunizing protection of vaccination. In these cases it is 

 often not merely a decimation which results, but it may be a destruc- 

 tion of more than half of the entire population. In a few isolated 

 instances almost every individual of a tribe or village has been cut off. 

 Not the sins alone of the fathers but some of their safeguards are 

 visited upon the children. The clean living that drove away leprosy 

 from English soil and that so widely substituted the gout for the 

 'King's evil,' has tinctured the blood of the children of the men who 

 fought at Naseby and learned a lesson in humanity from Howard. 



It will be seen that the whole question pivots upon vaccination. It 

 is necessary to look critically upon this means of securing immunity, 

 for the procedure is again under the searchlight. 



All said and done, vaccination is an invaluable means of securing 

 immunity against smallpox, but it is not a perfect means. What 

 artificial conquests of man are rounded to the perfection-point? Every 

 one knows that the finest double-screw steel vessel that steams across 

 the Atlantic can be crushed by a single blow of the arm of the sea if 



