GENERAL BACTERIOLOGY 
117 
applications of tincture of iodine, apply a tourniquet 
half way up the arm, to make the veins stand out promi¬ 
nently, with a sterile all-glass Luer syringe withdraw 5 
to 10 c. c. blood. 
If typhoid is suspected, pour about 5 c.c. of blood into 
a flask with bile-peptone-glycerin medium, incubate for 
12 hours, and then make transfers to ordinary broth 
(about 1 to 2 c.c. of bile medium) or make plates on 
Endo’s medium. If septicemia or pneumonia are thought 
of, pour 1 to 2 c.c. of blood into each of 3 or 4 flasks 
with glucose meat infusion broth. 
A very simple and a very good method of obtaining 
pure blood cultures—a method that produces fewer con¬ 
taminations than any other—is the use of the special 
tubes which are now on the market (see Fig. 21-B) ; 
they are practically large Keidel vacuum tubes (which 
are used for obtaining blood for Wassermann and similar 
tests) containing various culture media; the outer tube 
(A) is taken off, after the arm is prepared in the usual 
way (scrubbed with alcohol) a turniquet is placed above 
the elbow bend and the patient is told to keep the fist 
shut tight, in order to make the veins stand out, the 
needle (B) is thrust into the vein, the sealed end (D) 
of the tube containing medium (E) is broken with one’s 
thumb and the index finger, within the rubber tubing 
(C), and then the vacuum in (E) causes the blood to 
flow through the needle (B) and the rubber tubing (C) 
into the medium in (E). 
As one can readily see, the blood is never exposed 
to the air contamination as it flows from the vein into 
the tube containing the medium; neither is the medium 
exposed to contamination. 
10. Sputum.—Sputum is usually examined for tubercle 
bacilli. A thick yellowish piece should be chosen and 
smeared on a glass slide in a usual way, dried and fixed 
