CHANGES IN FRESH BEEF DURING COLD STORAGE. 9 
ter one hind quarter was cut from the carcass, wrapped in cheese- 
cloth previously soaked in a solution of bichlorid of mercury 
(1-1,000) and then in dry cheesecloth and paper, and was at once 
transported to the laboratory by means of a motor truck, the trip 
requiring about half an hour. 
Preparation of samples. — At the laboratory the hind quarter was 
transferred at once to a small bacteriological workroom, the floor, 
walls, and ceiling of which had been sprayed a short time previously 
with a disinfectant solution. Large plugs of meat, approximating 
3 to 4 inch cubes, were cut from the muscular tissue, avoiding con- 
nective tissue and fat as much as possible. Sterile instruments 
were used in taking the samples and great care was exercised to 
make this procedure as nearly aseptic as possible. In taking the 
samples the outer portions of the hind quarter which had come in 
contact with the bichlorid gauze were of course rejected, these por- 
tions being trimmed away. The samples, which weighed from 274 
to 512 grams, were immediately transferred to sterile crystallizing 
dishes fitted with glass covers. The dishes were then weighed and 
the covers sealed with adhesive tape and over the tape were placed 
strips of tin foil. This was done for the double purpose of prevent- 
ing evaporation and bacterial contamination from the outside. The 
dishes containing the samples were then placed in the incubator. 
Bacteriological control of experiments. — The samples were care- 
fully inspected from day to day for evidences of bacterial growth. 
As the moist surfaces of the meat samples and the exuded juices fur- 
nished an excellent medium for the growth of contaminating micro- 
organisms, such growths, when they occured, soon became percepti- 
ble to the naked eye. Out of a total of 36 samples, 24 showed visible 
bacterial growths upon incubation and these were rejected. In the 
case of these samples it was not necessary to make cultures, as the 
bacterial growths were quite apparent to the naked eye ; in doubtful 
cases stained preparations were made. Nine of the samples showed 
no visible bacterial contamination after incubation periods ranging 
from 7 to 100 days, and these were subjected to careful bacteriological 
examinations in order to establish their sterility. In examining the 
samples bacteriologically, cultures were first made from the exuded 
juice and the outer portions of the meat samples. The samples were 
then cut in half with sterile instruments and cultures taken from 
the inner portions. Both anaerobic and aerobic cultures were made 
on several kinds of media. The 9 samples which showed no visible 
bacterial growths were found to be sterile upon bacteriological exami- 
nation, and these samples were passed for chemical examination and 
study. 
/Sampling of fresh material. — The samples having been taken for 
incubation, a composite sample of the lean meat was taken for analy- 
