ON CLASSIFICATION OF PERSONS EXPOSED TO SiMALLPOX. 505 



Note on the Principle of Classificalioii. — The purpose in view 

 is to bring the protective power of vaccination as now practised 

 to the test of experience ; and that in the face of some lingering 

 scepticism on the part of a section of the public, and of a few 

 eccentric members of the medical profession. It is most necessary, 

 therefore, that records intended — not to show the efficacy of 

 vaccination against small-pox, but still farther to test it, should 

 be scrupulously compiled ; and that in those cases in which cer- 

 tainty cannot be arrived at, the doubt should be recorded as against 

 vaccination. 



PROPOSITION II. 



The elements of classification of pei'sons who have been vacci- 

 nated in infancy or childhood are («) character of scar, (6) area of 

 ^car, and (c) age of the subject. 



Note on the Classification of Scars by Character. — The charac- 

 teristics of "good" and "indifferent" scars have been defined 

 by Marson in words which are as forcible to-day as when 

 they were first uttered nearly forty years ago. A " good " scar, 

 he says, may be described as distinct, foveated, dotted or indented, 

 in some instances radiated, and having a well, or tolerably well- 

 defined edge ; an " indifierent " cicatrix as indistinct, smooth, 

 without indention, and with an irregular, ill-defined edge. But 

 it will be observed that before deciding whether a scar is good or 

 indifierent, it is necessary to inquire into its origin. This is a 

 question which has hitherto received little attention. Vaccine 

 scars have the appearance described by Marson ; but is that 

 appearance exclusively theirs — have they in reality characteristics 1 

 As soon as I began to examine cases of suspected small-pox, in 

 judging which the fact of former vaccination or no n- vaccination 

 is occasionally an aid to diagnosis — as soon as I began to examine 

 with this object great numbers of persons of all nationalities 

 and all conditions both on shore and on shipboard, I was struck 

 with the very large share that position, and the verbal evidence 

 ofiered by the subject, in reality have in forming an opinion 

 as to the cause of the scar in very many cases. Especially was 

 I struck with the frequency with which firemen and engineers 

 show small scars which are " distinct, foveated, dotted or indented, 

 having a well, or tolerably well-defined, edge " — scars which 

 nevertheless are not due to vaccination at all, but to mere super- 

 ficial burning. A different kind of difficulty arose, such as the 

 following : — A woman who had been exposed to infection fell ill 

 while under observation, and suffered quite clearly from small-pox, 

 although in a much modified form. In the face of her reported 

 statement that she was unvaccinated — a statement she supported 

 with circumstantial details of an unsuccessful attempt to get 

 vaccinated made within her recollection, the modification of 



