( a ) C h l o r o f o r m i n g .
(
b
) E t h e r .
(
c
) C l o v e o i l .
(d) Brilliant green.
(e) Untreated glycerine.
8
REPORT ON THE WORKING OF THE KING INSTITUTE, GUINDY
Institute for the past three years. As a result of these experiments
sufficient evidence has now been collected to make a definite pronounce
- m e n t o n t h e s u b j e c t , a n d t h e r e s u l t o f t h e e x p e r i m e n t a l w o r k h a s b e e n
reported to Government in this office letter Cur. No. 4218 of 1924. It is
not possible to give a detailed description of the various experiments that
have been carried out in this Institute as it would take up too much space
in this report, but a summary of the experiments and the conclusions
arrived at is given below:
—
"The following methods of purifying vaccine lymph have been
tested under the conditions which obtain in the Madras Presidency:
—
The results obtained are as follows:
—
( 1 ) C h l o r o f o r m i n g l y m p h r e d u c e d t h e b a c t e r i a l c o n t e n t t o i t s
correct limits. Exposure of ten to twelve minutes produces least deterio
-ration in the potency.
( 2 ) S t e r i l i z a t i o n b y e t h e r . — S o f a r t e s t e d b y u s , e t h e r w a s f o u n d
to take too long, and to be uncertain in its effects.
( 3 ) C l o v e o i l p r o v e d t o b e a s a t i s f a c t o r y r e a g e n t f o r p u r i f i c a t i o n
purposes. The time required was four days' exposure and the amount of
deterioration of potency was small.
( 4 ) B r i l l i a n t g r e e n . — B r i l l i a n t g r e e n i n d i l u t i o n s o f o n e i n t e n
thousand and one in five thousand, produced satisfactory bacterial purifi
- c a t i o n i n a b o u t f o u r d a y s . T h e l o s s o f p o t e n c y w a s i n a p p r e c i a b l e . T h e
great disadvantage of this method is the extreme care that is required in
the addition of sodium hydrosulphite to stop the further action of
brilliant green.
( 5 ) O u r t e s t s s h o w t h a t g l y c e r i n e l y m p h w i t h o u t a n y p a r t i c u l a r
treatment is purified to a satisfactory degree within four days of exposure
to the ordinary temperatures found in the Madras Presidency. As the
amount of deterioration in the lymph produced by glycerine is a common
factor to all methods of purification and as the more rapid methods of
purification may produce further deterioration, we see no advantage in
introducing any of these rapid methods. We therefore recommended
that no special means of purification be introduced and that untreated
glycerine lymph be the authorized lymph for issue to the Madras
Presidency."
As the result of these experiments Government in their G.O. No.
Press 1972, P.H., dated 22nd December 1924, have approved of the use of
untreated glycerine lymph in this Presidency.
(3) Tests with experimental lymphs prepared in various other ways
. — E x p e r i m e n t s i n c o n n e x i o n w i t h t h e m a n u f a c t u r e o f d r i e d l y m p h , o r c h i t i c
vaccine, and rabbit neuro-vaccine, referred to in the last year's report,
have been held in abeyance for the present, but will be resumed at a
future period. Experiments were made with crude pulp treated with
carbolised saline, with lymphs exposed to various temperatures for
varying periods, with lymph treated with arc-rays and also with dried
vaccine lymph. The results, however, were not so satisfactory as those
obtained with the usual stock lymph.
It is most essential that every batch of vaccine lymph should be
tested from time to time during its storage, and before its issue to the
Presidency, with a view to ascertaining its potency. This is invariably
done on calves, but it is equally essential that a lymph manufacturing
centre like the King Institute should have always available near a
hand a sufficient number of human cases for vaccination and obser
- v a t i o n o f r e s u l t s . F o r t h i s p u r p o s e i t i s v e r y n e c e s s a r y t h a t s o m e o f t h e