4th. How soon does the arcola arrive at its greatest height in those countries?
The arcola surrounding the vaccine vesicle is, I think, at its greatest height about the eleventh or twelfth day after vaccination, if the lymph used has been genuine.
5th. Does small-pox prevail there?
6th. Does small-pox prevail there after vaccination?
Small-pox prevails occasionally, and there are instances of its having occurred even in a confluent form after vaccination: one genuine instance of this kind came under my notice in the year 1824, in the person of a liberated African girl, of about sixteen years of age; vaccination had been performed in this case, by the late Dr. Nicol, Deputy Inspector of Hospitals, and was considered satisfactory; the case proved confluent; the secondary fever was accompanied by a severe diarrhoea, which carried off the patient about the thirteenth day. Another well authenticated instance of the same fact, occurred in the early part of the present year, in the family of a respectable Nova Scotian settler; other cases of a similar nature have been reported by the inhabitants; but I do not consider that, in these cases, the proofs of a pure previous vaccine disease have been satisfactorily established; when vaccination has been carried on for some time, from the same stock of lymph, the disease is apt to degenerate and become spurious, from which cause we require a frequent renewal of lymph from England, in order to keep it in continuous and successful operation; the spurious disease, on the fifth day, generally shews itself in the form of a small globated papula; on the eighth day, it presents sometimes an ash-coloured pustule, containing purulent matter; at other times, and less frequently, a brown-coloured scale, having a small quantity of purulent matter under it, capable of producing, by innoculation, a disease similar to itself; the great prevalence of a disease among the negro population, called "craw craw," is considered as materially influencing that change in the properties of the pure vaccine lymph, which has been just noticed: that apathy and indolence of which I have already accused the negro population, leads them to consider the appearance of disease in the arm, after vaccination, as the test of safety from small-pox, great as the difficulty sometimes is, in getting them to bring forward their children for vaccination, it is still greater to procure the examinations in its progress and maturation; the mere appearance of disease in the arm, is supposed to carry along with it immunity from small-pox; and, on the occurrence of the epidemic at an after period, it may be easily foreseen how wretchedly and how fatally this confidence in the spurious disease may be misplaced; I, therefore, do not consider, that, in all the cases spoken of among the inhabitants, as cases of small-pox occurring after vaccination, there existed satisfactory proofs of the patient having previously undergone the genuine vaccine disease; yet, I am sorry to say, that from such occurrences as these, vaccination has rather lost ground in the opinion of the negro population.
7th. Is small-pox an increasing malady?
Small-pox is not an increasing malady; it is generally introduced here from the slave cargoes of vessels detained by the squadron, and sent here for adjudication; were this source of its renewal removed, I am persuaded that small-pox would, in the course of a few years, be almost unknown in this part of Africa.
8th. Can the vaccine virus be retained on points and glasses, so as to be fit for use?
The vaccine lymph, if taken on points, will not retain its virulence seven days in this country: this observation is established by repeated trials; if taken on glasses, I would not be disposed to depend on its activity when kept longer than fourteen or sixteen days, though I have known it sometimes to retain its original properties for four or five weeks; if preserved in glass bulbs, hermetically sealed, in the manner practised by the National Vaccine Institution, I have known its properties unimpaired after keeping for three months; repeated trials have convinced me of the excellence of this mode of preserving the vaccine lymph, and, I believe it to be the best and surest that has been yet devised of transmitting the lymph from England to tropical countries: next to this method, I believe the crusts have proved the most successful.
9th. Are the young negro population pitted with the small-pox?