TECHNIQUE. 
137 
Milk and Water. 
Specimens should be collected in glass-stoppered 
bottles, of 4- or 6- ounce capacity, which are sterile. 
Specimens of milk should be well mixed before the 
sample is taken. Specimens of both milk and water 
must be kept cold and, if it is necessary to send them 
any distance, they must be packed in ice. 
All kinds of specimens should be labeled with 
the names of the patient, the physician, the date, and 
character of the examination desired. 
Aspirations and Blood Cultures. 
The preparation of the patient for the aspiration n ^ C e‘ of 
of fluid from the body cavities, for lumbar puncture, 
and cultures from the blood must be performed with tions 
the greatest care, to insure the patient against infec¬ 
tion and to prevent the contamination of the specimen 
with other bacteria, particularly those in the skin. 
For aspirations of the chest or joints and for 
lumbar puncture, the skin should be cleansed with 
benzene and then tincture of iodine applied. In taking 
cultures from the blood this method is not always suit¬ 
able, because the tincture of iodine discolors the skin 
so much that the veins cannot be seen clearly. The 
veins usually selected are at the bend of the elbow. 
The skin is cleansed first with green soap and water, 
then with alcohol and ether. A towel wet with bichlor¬ 
ide of mercury is placed over the skin and allowed to 
remain for one hour. Before the culture is taken the 
