344 Dr. Murray on Vacchudion. 



however, to impute failiuT in early age, more to want of propei 

 attention to the many eirenmstances upon which perfect and 

 satisfattory vaccination rest, than to the premature a2;e of tlie 

 subject." 



Dr. Gregory said, tliat " thenofion of the insecurity of Cow- 

 Pox depending upon the operation being performed at too 

 early a period of life, s^ not" (as I siip|/osed) •' a novel one, 

 as he hud read of it frequently, though he could not put hi;^ 

 linger on the author who hud mentioned tiie <loctrine — he had 

 probably met with it in Reviews, or JMuiirazines, but tiie notion 

 had never become popular, because it is neither supported by 

 facts, nor by analogy : allowing the analogy of scarlatina to be 

 in its favor," (which he thouglrt not proved) " he considered 

 that of Small-Pox to be diicciK' against it, as natural Small- 

 Pox occurs just as often to infants as to adults, the suscep- 

 tibility to that disease being complete as soon as the child is 

 born ; and it is froni a perfect conviction' of this fact in 

 pathology, that parents desire and physicians recommend 

 vaccination within the first three months. Had any dilFerenco 

 in the protective power of Cow-Pox been observed in those 

 vaccinatrd at the age of a few months and those in whom the 

 operation had been deferred till three or fonr years of age," 

 (as queried by me) "it must iieccssarili/,'' he said, "have 

 attracted the notice of parents ; and the circumstance of its not 

 being noticed, was, to his mind, vr oof satisfactory that it does 

 not exist. That /»w<? diminishes the protecting virtue, he hel'cJ 

 to be a clearly ascertained fact; and, therefore, witb regard to 

 the propriety and probable effects of re-vaccinatiori, he was m 

 perfect accordance with me, thOugR'lie came to the same point 

 by a diflerent route— bis belief however is, that the system is as 

 thoroughly sataralle in infancy as in childhood ; and, besides, 

 even supposing infants only a month old to be comparatively 

 insusceptible of receiving Small-Pox or Cow-Pox by inoculation, 

 it does not thence follow that the disease if produced, and if it 

 runs its normal course, should' confer less security — in other 

 words, that difficult susceptibility and impaired protective 

 power are not at all necessarily associated." 



In regard to Mr. Bruce's observations, I have to say, that 

 although be may probably bfc very right that failures in early 

 life are more frequently owing to want of proper attention to 

 the other many circumstances upon which perfect and satisfac- 

 tory vaccination rests, than to tbe premature age of the subject; 

 yet, as it is according to general experience, that infants sulFci' 

 comparatively very little constitutional disturbance under vac- 

 cination, I am inclined to consider this an indication that their 

 constitutions do not thoroughly sympathise, aud that they are 

 less perfectly susceptible of the assimilating action of the 

 vaccine disease than those of older subjects, although it is laid 



