10 BULLETIN 433, U. S. DEPARTMENT OF AGRICULTURE. 
sis and placed in cold storage until the next day, when it was pre- 
pared for chemical examination. Analytical work was started prac- 
tically 21 hours after slaughter, during which time the material used 
for analysis had been in cold storage 17 hours. All work in the 
preparation of the material for analysis, including the weighing of 
the material for individual determinations, was carried on in a refrig- 
erated room at a temperature between 32° and 40° F. After the 
fresh material had been ground as finely as possible and transferred 
to glass jars which were then tightly stoppered, chemical work was 
started forthwith. In the case of the incubated samples, as soon as 
cultures had been taken for bacteriological examination, the dishes 
were again sealed and placed in a refrigerated room at a temperature 
of 21° F. for 2 or 3 clays or until results had been obtained from 
the bacteriological examination of the samples. The meat was then 
prepared for analysis by the same methods used with the fresh 
material. 
PHYSICAL AND ORGANOLEPTIC CHANGES. 
The sterile samples showed increasing losses in weight as the ex- 
periment progressed, ranging from 0.8 per cent in the sample in- 
cubated 7 days to 10.08 per cent in the sample incubated 100 days. 
Certain observations on changes in the character of the samples 
during incubation may be of interest. The sample which had been 
incubated 7 days showed the following characteristics : There was no 
apparent disintegration of the tissues and the piece of meat had 
retained practically its original form; considerable juice had exuded 
which had turned light brown in color and which contained consid- 
erable sediment of a grayish-white color; after the dish had been 
opened and cultures for bacteriological examination had been taken, 
a strip of moist lead paper was inserted as a test for hydrogen sul- 
phid, but no reaction was obtained; the exposed surface of the meat 
was light brown in color, while the surface which rested on the bot- 
tom of the dish was bright-pink in color. The cutting of a cross 
section showed that the meat was somewhat rubbery in texture and 
not noticeably tender. The cross section showed a brown zone ex- 
tending inward for a distance of about one-fourth of an inch from 
the surface, except where the meat had rested upon the bottom of 
the dish, where the pink color extended to the surface. The interior 
of the sample was of a uniformly bright-pink color. The meat had a 
pleasant odor, somewhat similar to that of rare roast beef. The re- 
mainder of the sterile samples, which had been incubated for periods 
ranging from 11 to 100 days, showed characteristics so similar to 
those of the sample just described that a separate description of each 
sample does not seem to be necessary. 
