APPENDIX. 577 



About one-fourtli of the wliole number were vaccinated directly 

 from tlie pustules of patients laboring under tlie disease ; while 

 the remaining three-fourths were vaccinated from crusts, or from 

 virus which had been several days on hand, I did not pass by a 

 single opportunity for securing the crusts and virus from the 

 arms of healthy patients; and to avoid, as far as possible, the 

 chance of giving rise to a disease of a spurious kind, I invariably 

 made use of those crusts and that virus, for the purposes of vacci- 

 nation, which had been most recently obtained. To secure, as 

 far as possible, against the chances of escaping the vaccine disease, 

 I invariably vaccinated in each arm. 



Of the whole number of Indians vaccinated, I have either 

 watched the progress of the disease, or examined the cicatrices of 

 about seven hundred. An average of one in three of those vac- 

 cinated from crusts has failed, while of those vaccinated directly 

 from the arm of a person laboring under the disease, not more 

 than one in twenty has failed to take effect — when the disease did 

 not make its appearance after vaccination, I have invariably, as 

 the cases came under my examination, revaccinated until a favor- 

 able result has been obtained. 



Of the difierent bands of Indians vaccinated, a large proportion 

 of the following have, as an actual examination has shown, under- 

 gone thoroughly the effects of the disease ; viz : Sault Ste. Marie, 

 Keweena Bay, La Pointe, and Cass Lake, being seven hundred 

 and fifty-one in number ; while of the remaining thirteen hundred 

 and seventy-eight, of other bands, I think it may safely be calcu- 

 lated that more than three-fourths have passed effectually under 

 the influence of the vaccine disease : and as directions to revac- 

 cinate all those in whom the disease failed, together with in- 

 structions as to time and manner of vaccination, were given to 

 the chiefs of the different bands, it is more than probable that, 

 where the bands remained together a sufficient length of time, 

 the operation of revaccination has been performed by themselves. 



Upon our return to Lake Superior, I had reason to suspect, on 

 examining several cicatrices, that two of the crusts furnished by 

 the surgeon-general, in consequence of a partial decomposition, 

 gave rise to a spurious disease, and these suspicions were con- 

 firmed when revaccinating with genuine vaccine matter, when 

 the true disease was communicated. Nearly all those Indians 

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