AGf~ICULTURAL RESEARCH, PUSA.

BR8 PRACTICAL BACTERIOLOGY
for two to four days at B7'Q C. The culture is
then heaLed at HOl) C. for Imli-an-hour to Ull
spreading non - sporing organisms such as
B. proteus. 'rhc condensation water of a
peptic-hlood-agar slope is inoculated from the
heated culture, and incubated at B7° C. under
anaerol?ic conditions. After twenty-four to
forty-elght hours the edge of the culture
is. examined with a low-power binocular
Ilncroscope or hand-lens, when a growth of
tetanus bacilli is seen as It mass of very fllle
filaments. Subcultures from. the marginal
growth usually yield pure cnlturcs of B. tetanL
(It is advantageous to keep Lhe peptic-bloodagar
tubes until the surface of the mcdium is
dry at the top.)
THE ANAEROBIC BACILLI OF INFECTED WOUNDS
l'hesc organisms, belonging to the genus Clostridium,
are associated with rapidly spreading' inflammatory
oedema, necrosis and gangrene of the tissues, and
gas production, occurring as a complication of wound
infection. They are all sporing organisms and their
source is mainly animal exercta. 'f'hey were responsible
for the so-called gas-gangrene which Was
so prc\ralcnt among the armies in Europe during the
War. The heavily manured soil of the cultivated
fwlds of France contained abundant spores capable
of remaining viahlc for long periods of time, and the
infection resulted from the contamination of wounds
with soil.
samplc (If the mixture diluted with water gives a pCl'Il1anganatcred
colour with cresol-red iudicator. Purc Hel iH now alltled
drop by (hop until ll. sample of the mixture shows almost no
change of colour with cresol-red, but a definite red tint with
phenol.reel. It is important to avoid excess of ncid. Chloro.
form, 0·25 pCI' cent., is added and the mixtul'e shaken vigorously.
'L'his peptic digest of blood ],;ceps well for months. For llse it
is hentcd to 55° C. for thirty minutes to rcmove the chloroform,
and added tu bruth 01· agar in the proportiuIl of 2 to () per cent.