utaneously with filtered glucose bouillon
cultivations (toxins?) and observe the result.

(B) 1. Emulsify the remainder of the deposit with 5 c.c. sterile
bouillon and inoculate two guinea-pigs, thus: guinea-pig a,
subcutaneously with 1 c.c. emulsion; guinea-pig b, subcutaneously with
2 c.c. emulsion; and observe the result.

2. If either or both of the inoculated animals succumb, make complete
post-mortem examination and endeavour to isolate the pathogenic
organisms from the local lesion. Confirm their identity as in A5 and 6
(_vide supra_).

~5. Bacillus Tuberculosis.~--

(A) 1. Inoculate each of three guinea-pigs (previously tested with
tuberculin, to prove their freedom from spontaneous tuberculosis)
subcutaneously at the inner aspect of the bend of the left knee, with 1
c.c. of the deposit emulsion remaining in one or other tube (D^{1} or
D^{2}).

2. Introduce a small quantity of the cream into a subcutaneous pocket
prepared at the inner aspect of the bend of the right knee of each of
these three animals. Place a sealed dressing on the wound.

3. Observe carefully, and weigh accurately each day.

4. Kill one guinea-pig at the end of the second week and make a
complete post-mortem examination.

5. If the result of the examination is negative or inconclusive, kill a
second guinea-pig at the end of the third week and examine carefully.

[Illustration: FIG. 215.--Cadaver of guinea-pig experimentally infected
with B. tuberculosis.]

6. If still negative or inconclusive, kill the third guinea-pig at the
end of the _sixth_ week. Make a careful post-mortem examination.
Examine material from any caseous glands microscopically and inoculate
freely on to Dorset's egg medium.

NOTE.--Every post-mortem examination of animals infected
with tuberculous material should include the naked eye and
microscopical examination of the popliteal, superficial and
deep inguinal, iliac, lumbar and axillary glands on each
side of the body, also the retrohepatic, bronchial and
sternal glands, the spleen, liver and lungs (Fig. 215).

(B) 1. Intimately mix all the available cream and deposit from the milk
sample, and transfer to a sterile Erlenmeyer flask.

2. Treat the mixture by the antiformin method (_vide_ Appendix, page
502).

3. Inoculate each of two guinea-pigs, intraperitoneally, with half of
the emulsion thus obtained.

4. Kill one of the guinea-pigs at the end of the first week and exami