8
REPORT ON THE WORKING OF THE KING INSTITUTE, GUINDY
These figures simply corroborate the results obtained in previous investiga-
tions on this subjects.
(2) Experiments as to the feasibility of purifying glycerinated lymph by
the chloroform process. —The value of the chloroforming process as a means of
purifying lymph has been the subject of exhaustive tests throughout the year.
Eighty-seven different batches of lymph have been tested and 2,278 children have
been vaccinated with these lymphs. In order to get a carefully controlled test
each batch of lymph after being diluted with glycerine to the correct strength
was divided into two equal parts, the one being subjected to chloroform vapour
for varying periods from 10 to 15 minutes, the other remaining untreated. The
number of extraneous bacteria present in the lymph was then estimated and the
percentage of purification calculated. Both the chloroformed and untreated
samples were issued together and used under similar conditions on the same
children, one arm being vaccinated with the chloroformed and the other with
unchloroformed lymph and the results noted. All extraneous factors were thus
avoided and definite conclusions could be drawn as to the effect of the chloroform-
ing process on the lymph.
Taking the figures as a whole there is not much difference between the
results obtained with the treated and untreated lymphs (statement No. 8). The case
and insertion success rates for the untreated lymph (88 . 7 and. 80 . 8) are slightly
better than those of the samples exposed to the chloroform vapour (85 . 8 and 79.0).
Further, the number of lymphs producing a case success rate of over 90 per cent
is distinctly greater in the untreated series although the insertion success rate is
better in the case of the chloroformed lymph (statement No. 9). The reduction in
the extraneous bacteria was always much more marked in the case of the treated
samples. The number of bacteria per c.c.m. varied between 580 and “countless,
for the untreated and 0 . 3 and 5 . 6 for the treated lymphs. The results of the ex-
periments so far conducted would indicate that the chloroform process undoubtedly
depreciates the potency of the lymph to some extent especially if carried on
sufficiently long to kill all bacteria present in the lymph. This vaccinicidal action
is somewhat uncertain and is not fully under control, some batches of lymph
giving evidence of very considerable destruction, others although subjected to the
same treatment showing little or no degeneration.
While this want of control exists, it would be inadvisable to introduce the
chloroforming process into general use although it presents very considerable
advantages in that it produces a much purer lymph which should be able to with-
stand the effect of heat better than a lymph containing a larger number of extra-
neous organisms, The discovery of the various factors which cause the present
want of control will be the subject for investigation next season and it is to be
hoped that, once these factors have been discovered and the necessary modifications
have been introduced into the purifying process, it will be possible to issue a
potent and highly purified lymph from the Institute.*
(f ) Yield of pulp .—Statement No. 10 gives the average yield of pulp per calf
per month for the year under report. It is satisfactory to note that the average
weight of pulp per calf has again increased from last year's average, i.e., 20.2
grammes to 20.4 grammes. This means a further diminution in the number of
calves used and a corresponding reduction in the cost under the heading, purchase
of calves. The number of calves used during the present year was 825 as
opposed to 997 purchased last year. This represents a saving of Rs. 1,183. It
was pointed out last year, however, that the limit in this direction had probably
been reached and that slight variations from year to year would have to be
expected in future.
(ii) BACTERIOLOGICAL SECTION.
(a) Preparation and supply of bacterial vaccines.—The number of doses of
bacterial vaccines supplied during the year was 71,654 as compared with 61,562
* This statement must not be misunderstood. Glycerine by itself has a very considerable purifying
action on vaccine lymph. The great advantage of the chloroforming process lies in the fact that the purification
takes place in a much shorter time. A lymph can thus be issued in the purer state much sooner after preparation.