TUBERCULOSIS. 157 
6. Detection of Tubercle Bacteria in Milk. 
(1) First Method.’ 
(2) To 50 c.c. of suspected milk add 10 cc. of 
carbolic acid. 
(6) Shake vigorously for two to five minutes. 
Pour into a sedimenting glass, cover, and allow to 
stand for twenty-four hours ; or use a centrifuge. 
(c) With a pipet remove the deepest layer of sedi- 
ment and prepare films. 
(2) Dry and pass three times through flamie. 
(e) Pass through equal parts of ether and alcohol. 
(/) Dry and pass three times through the flame, 
and stain as directed for sputum. 
(g) Mount and examine with the 5 inch oil- 
immersion lens. 
(2) Second Method. 
(2) To 20c.c. of the milk add 1 c.c. of a 50 per 
cent. potash solution. 
(6) Heat in boiling water until the mixture turns 
yellowish brown. 
(c) Add 20 c.c. of acetic acid, shake, heat again 
for three minutes, and centrifuge. 
(d) Wash the sediment with hot water, again 
centrifuge, and make cover-glass preparations from 
the second sediment. 
(e) Stain as directed for sputum. 
1This method may also be applied to the detection of 
tubercle bacteria in sputum when present in very small 
numbers, using 10-15 c.c. of sputum, Io c.c, of water, and 6 
c.c. of carbolic acid. 
