470 BACILLI IN CHRONIC INFECTIOUS DISEASES. 
keeping well. The staining is effected more quickly if heat is ap- 
plied. The tubercle bacilli stain by Gram’s method, but this is not 
to be recommended for general use, owing to the fact that the pro- 
toplasm of the rods is frequently contracted into a series of spheri- 
cal, stained bodies, which might easily be mistaken for micrococci. 
The examination of sputum for the presence of the tubercle ba- 
cillus is recognized as a most important procedure for the early diag- 
nosis of pulmonary tuberculosis. It is at- 
tended with no special difficulties, and every 
physician should be acquainted with the 
technique. 
The patient should be directed to expec- 
torate into a clean, wide-mouthed bottle or 
glass-covered jar the material coughed up 
from the lungs, and especially, in recent 
cases, that which is coughed up upon first 
rising in the morning. This should be 
placed in the physician’s hands as promptly 
as possible ; although a delay of some days 
does not vitiate the result, and the tubercle 
bacilli may still be demonstrated after the sputum has undergone pu- 
trefaction. Itis well to pour the specimen into a clean, shallow vessel 
having a blackened bottom—a Petri’s dish placed upon a piece of dead- 
black paper will answer very well. In tuberculous sputum small, len- 
ticular masses of a yellowish color may usually be observed, and one 
of these should be selected for microscopical examination, by picking 
it up with a platinum needle and freeing it as far as possible from 
the tenacious mucus in which it is embedded. If such masses are 
not recognized take any purulent-looking material present in the 
specimen, whether it be in small specks distributed through the mu- 
cus, or in larger masses. A little of the selected material should be 
placed in the centre of a clean cover glass and another thin glass 
cover placed over it. By pressure and a to-and-fro motion the mate- 
rial is crushed and distributed as evenly as possible; the glasses are 
then separated by a sliding motion. The film is permitted to dry by 
exposure in the air. When dry the cover glass, held in forceps, is 
passed three times through the flame of an alcohol lamp or Bunsen 
burner to fix the albuminous coating. Too much heat causes the film 
to turn brown and ruins the preparation. The staining fluid (Ziehl’s 
carbol-fuchsin) may then be poured upon the cover glass, or this may 
be floated upon the surface of the fluid contained in a shallow watch 
glass. Heat is now applied by bringing the cover glass over a 
flame and holding it there until steam begins to be given off from 
the surface of the staining fluid; it is then withdrawn and again 
sis in sputum, x 1,000. (Baum- 
garten.) 
