xvi.
APPENDICES.
legs being widely stretched apart; the tail is also tied out of the way. The whole surface
of the abdomen as far forward as the costal arch and inner surface of both thighs and the
folds of the groins are carefully shaved. The shaved surface is then washed thoroughly
with soap and warm water, and finally scrubbed with corrosive sublimate solution, 1 in 1,000,
and carefully dried.
The whole surface is then carefully scarified by parallel incisions crossing each other
at right angles about ½ inch apart.
The incisions are several inches long and extend in
depth to the surface of the vascular layer of the skin. If the operation is carefully perform-
ed and care be exercised that the incisions do not reach deeper, very little pain is caused
to the calf; a certain amount of oozing of blood takes place from some parts of the incisions ;
this is wiped off before it has had time to clot and so close the incisions.
Vaccine glycerine lanoline paste is then rubbed into the whole extent of the incisions
with a spatula and allowed to dry.
A clean calico binder is then fastened over the vacci-
nated area and the calf is returned to the stable, where it is placed upon a wooden platform
with grass to lie upon, and loosely tied by head and legs to prevent it from licking or scratch-
ing the parts operated upon.
The calico binder is replaced by a clean one each morning.
On the fourth day defi-
nite signs of an eruption are visible, and the vesicles are generally sufficiently developed
for scraping by the sixth day, i.e, about 120 hours after operation. Sometimes it is advisa-
ble to wait another 24 hours to admit of the vesicles reaching their full development, but
there is a risk in the dry weather of their drying up before the lymph can be collected, un-
less their condition is carefully watched.
As soon as the vesicles are ready for collection of the pulp, the animal is again tied
upon the operating table in the same position as for vaccination. The operated surface is
washed lightly with soap and warm water, and rubbed with corrosive sublimate solution,
1 in 1,000, and dried ; thick scabs, if present, are removed and all superfluous moisture care-
fully got rid of.
With a small silver scraper, or a scalpel, the vesicles are now removed bodily, the
base being scraped once only. Care is taken to avoid collecting any blood with the lymph,
but there is necessarily a small quantity mixed with the scrapings. The vesicles from the
whole area having been scraped off and collected in a glass dish, the material so collected
is carried to the work-room and carefully weighed, then mixed by grinding with an equal
weight of pure glycerine, and stored in an air-tight bottle ; the calf has meantime had the
scraped area dressed with boracic acid and starch, and is then put back in the stable.
It
is returned to its owner so soon as it has recovered from the last operation.
The vaccine scrapings contain the whole substance of the vesicles including the thin
cuticle covering them. This has to be very carefully ground in a glass mortar to break up
the cuticle into very fine portions until the fluid becomes all but homogeneous in appear-
ance and consistency. On the day after collection, the vaccine glycerine, which consists of
equal parts of glycerine and vesicle scrapings, is again mixed and ground with an equal
weight of pure glycerine, the resulting fluid being of the proportions of 1 part of vesicle
scrapings to three parts of glycerine, i.e., 1 in 4.
In the earlier months of the year under review I used anhydrous lanoline in prepar-
ing the vaccine paste for distribution, following the method of my predecessor Dr. Fink.
The proportions of the ingredients of the vaccine paste distributed were vesicle scrapings
one part, pure glycerine one part, anhydrous lanoline two parts (strength 1 in 4).
The lanoline paste had a tendency to become mouldy in the wet weather, and it also
decomposed readily; after reading Dr. Copeman's treatise on vaccination and the prepara-
tion of vaccine with glycerine, which has been found to retain its properties for many
months in Europe, I decided to experiment with glycerine in the proportion of three parts
to one of vaccine vesicles. I have found since using this method that the vaccine paste
keeps perfectly sweet and free from smell for a long period, even up to two months after
preparation, the longest period for which I have tested it.
I found in a specimen of glycerine vaccine paste prepared in this way in August that it
retained its potency for vaccinating children over six weeks from the date of preparation.
Since January, however, I have not found that the vaccine paste prepared by this method
has retained its efficacy for a period exceeding 15 days, and I attributed this to the poor
quality of the vaccine obtained from the calves operated upon in February and March, which
were thin and in poor condition. The Civil Surgeon, Myaungmya, has given his opinion
that the vaccine glycerine paste now supplied by this institution is much superior to the
lanoline paste supplied previously. But I must admit that during the last three months,
January to March, the vaccine glycerine has shown a tendency to lose its efficacy sooner
than used to be the case in the later months of 1899, although the method of preparation has
remained the same. Beyond the poor condition of the calves used for operation, I am un-
able to suggest any cause for the rapid deterioration of the efficacy of the vaccine paste pre-
pared at this institution.
For vaccinating the calves I use glycerine vaccine of a strength one in four (vaccine
one part, glycerine three parts), to which I add lanoline two parts, making the strength of
vaccine equal to 1 in 6. In this case I always use freshly-prepared vaccine glycerine