1832.] Proceedings of Societies. 211 



there is no evidence of the true vaccine having been previously developed in that 

 case : moreover, as there is no proof that any of the cases had ever been exposed 

 to variolous contagion, in the interval between their alleged vaccination and the 

 appearance of the eruptive disease which formed the subject of report at the last 

 meeting; there is no reason to believe, that those individuals were ever insuscep- 

 tible of suffering from variolous or varioloid contagion ; he contends that we 

 Lave no reason to believe, if susceptibility to variola be once destroyed by true 

 vaccination, that persons are ever afterwards liable to suffer from variola. Dr. 

 Casanova further says, that before we can acknowledge a renewed susceptibility 

 to variola, in a person who has been once protected, we should ask two questions ; 

 1st, What reason have you for believing that this person has gone through the 

 regular course of true vaccination ? 2nd, What reason have you for believing that 

 this person has subsequently to vaccination been exposed to variolous contagion, 

 without contracting small-pox ? 



In reply to the 3rd question the author states, that either vaccine virus taken 

 from an unhealthy person ; or lymph from a perfect pustule used to vaccinate an 

 unhealthy person ; may certainly degenerate into an humor sai generis, and produce 

 a disease which affords no protection against small-pox. The particular disease 

 stated as likely to influence the character of the vaccine, and to impair its pro- 

 phylactic properties, are various cutaneous affections, which have been generally 

 acknowledged to be adverse to successful vaccination ; and some disordered 

 conditions of the absorbent system, which do not appear to have been before 

 particularly alluded to; but which the author asserts, have an unfavorable 

 influence, in as much as we are protected against variola, only by the vaccine 

 producing a constitutional as well as a local affection, which specific constitutional 

 affection may be frustrated by a disordered condition of the absorbent system. 

 The author also states, that cases have occurred, which render it probable, that 

 the influence of vaccination is altered when several diseases of the mucous mem- 

 branes occur during its progress, namely, aphthae, chronic gastro-enteritis, and 

 gonorrhoea. The author having, in concert with Dr. Romay, been engaged in 

 making numerous experiments relative to the vaccine disease, thinks he is autho- 

 rised to say, that he does not see any reason to acknowledge that vaccine matter 

 is capable of decomposition or change, except from the effects of exposure to air, 

 humidity, or light; and he considers that with due care in its transmission, the 

 specific properties of vaccine remain unaltered. 



Mr. Mercer's paper is in continuation of his report read at the former Meeting. 

 He observes that small-pox has been frequent and fatal among both Europeans 

 and Natives ; and a large proportion of the mortality has occurred in persons 

 advanced in years, and comparatively few in children. The author alludes to the 

 frequency of rubeola and varicella, as well as of small-pox, this season, and gives 

 a sketch of the distinctive characters of the two latter diseases, according to the 

 best authors, which must be familiar to the profession. Three cases are there 

 detailed, which may be numbered in continuation from those stated in the last 

 month's circular. 



Case VIII. A woman of European parents, 26 years of age, had fever on the 

 28th March ; vomiting took place, and the face was flushed. On the 30th an erup- 

 tion of numerous small pimples appeared; on the 5th April the face was swollen, 

 and the pustules very numerous, and filled with a thick opaque fluid ; many of 

 them coalesced : there was slight soreness of the throat, but no salivation, and no 

 fever after the eruption appeared. On the 10th day of the eruption and 12th of the 

 disease, the pustules were drying quickly on the face and some parts of the arms ; 

 and on the 19th day of the eruption a second set of crusts fell off. This person had 

 been vaccinated by Mr. Shoolbred when an infant ; one vaccine cicatrix is visible, 

 of the size of a garden pea, imperfectly marked with central depressions. 



Case IX. An Indo-Briton, 26 years of age, had fever on the 4th April, which 

 increased till the 7th, unattended with vomiting, except when medicine was taken. 

 On the 7th April an eruption of numerous small papulae appeared, some of 

 which on the 8th contained an opaque fluid, and on the 10th some of them on the 

 bands coalesced ; on the 12th desiccation commenced, and on the 14th the scabs 

 began to fall off. This person had been vaccinated at the age of 4 or 5 months 

 by Dr. Hare ; there is a small superficial cicatrix on the left arm slightly pitted. 



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