27
The comparative cost of cyllin and perchloride can be shown by a comparison
of the cost of 100 gallons of equally effective solution of each, English rates and
the cost of crude perchloride in bulk being taken as the basis : —
R S . A . P .
R
s . A .
P .
Cyllin1/3 gallon, cost
1 0 0 Perchloride 1 lb. cost
... 1 8 0
Water 99 2/3 gallons
Water 100 gallons
100 gallons cyllin— 100 gallons perchloride-
Strength 1 in 333
Strength 1-1,000
Costing...
... 1 0 0
Costing
... 1 8 0
But owing to difficulty of solution it is in practice necessary to use acid in
making up solutions of perchloride. The amount usually employed is one ounce of
crude hydrochloric acid to every three gallons of water. The cost of 100 gallons
of perchloride has to be raised therefore to Rs. 1-13-0. This estimate of the
comparative cost of cyllin and perchloride may be contrasted with the estimate of
Lieutenant-Colonel Bannerman, I.M.S., who has written on the subject.
Lieutenant-Colonel Bannerman, I.M.S., gives the effect of perchloride on the
plague bacillus as ten times that of cyllin. In this case the cost of 100 gallons of
perchloride solution would be to that of 100 gallons of equally effective solution of
cyllin, as Rs. 1-13-0 to Rs. 4. But this writer's carbolic acid co-efficient of cyllin
on plague is 25, as against 34 by Professors Simpson and Hewlett and 30 by Pro-
fessor Klein, so that the proportion might be as low as Rs.1-13-0 to Rs. 2 - 9 - 7 ,
even were perchloride so comparatively more effective than carbolic as the results
given by Lieutenant-Colonel Bannerman on the plague bacillus would indicate.
(Carbolic acid co-efficient of cyllin is equal to 25. Perchloride 10 times efficacy of
cyllin is equal to 250.)
If the action as a general and safe disinfectant be required, it is probable that
the figure 24 represents more closely than 250 the comparative merits of carbolic
acid and perchloride of mercury, and in this case the cost is considerably in favour
of cyllin, as noted in the original estimate by me.
APPENDIX IV.
THE EXTRANEOUS ORGANISMS OF VACCINE.
By the SUPERINTENDENT and Assistant Surgeon T. SEETHAPATHY IYER, I.M.S.,
Senior Bacteriological Assistant.
In order to arrive at a knowledge of the ordinary extraneous organisms in the
vaccine as produced by the Vaccine Section plates were made from vesicles from
25 calves at different stages and under such variations as vesicles used for vaccine
manufacture exhibit.
The procedure adopted was to remove the entire vesicle with a sweep of a
blunt sterile lancet, and to transfer this to a sterile test tube which was carried
to the laboratory. Small fragments approximately of the same size were then, as
far as possible, broken up in agar media which was then plated.
The investigation was unexpectedly simplified by the fact that the number of
species of organisms at all common was very limited. These species were as
follows :
—
1. By far the most numerous colonies were round, flat, white and opaque
with raised centre and entire edges; microscopically the organism is non-motile
and consists of groups of cocci staining readily with the ordinary analine dyes and
with Gram's stain. In broth (+10) it forms a homogenous turbidity and after a
certain time a scum on the surface; on slope agar it grows luxuriantly at room
temperature (30° c.) and at 37° forming an enamel like heavy growth. It does not
produce gas in glucose media and is a facultative anærobe growing however
better under ærobic conditions. This organism is identical with or closely related
to the Staphylococcus epidermidis albus.