42 
Journal of Agricultural Research 
Vol. VII, No. i 
as compared with that of the 9 other samples was reasonably good 
evidence that they also were sterile. 
Early in the course of the experiments it was noted that the exposed 
surfaces of the samples had turned light brown in color, in contrast to 
the red color of fresh lean beef, while the surface that rested on the bottom 
of the dish had become bright pink in color. When a cross section was 
cut through a sample, it was found that the brown color extended to a 
depth of about one-fourth of an inch, the width of the zone increasing 
somewhat with the period of incubation, while the interior of the sample 
was of a uniform bright pink color. In a few cases the meat samples 
rested in the dishes in such a way as to pocket some of the exuded juice 
and protect it from the air. In these instances the juice had a peculiar 
dark purplish red color, as compared with the muddy brown color of the 
juice that had been exposed to the air. After the meat was ground for 
analysis it soon turned brown in color. At first it was assumed that the 
production of the pink to purplish red color was due to a simple reduction 
of oxyhemoglobin to hemochromogen. A spectroscopic examination of 
the 0.9 per cent sodium-chlorid extract of the sample that had been 
incubated for 7 days showed that the coloring matter was not hemo¬ 
chromogen, and that oxyhemoglobin and hemoglobin also were absent. 
These facts led to a careful study of the color of a number of samples 
incubated for various periods of time, with the following results: 
Sample incubated eor 7 days. —The exposed surface of the sample 
was light brown in color, while the surface that rested on the bottom of 
the dish was bright pink. When a cross section was cut through the 
sample, the brown color was found to extend to a depth of about one- 
fourth of an inch from the surface, while the interior of the sample was 
uniformly bright pink in color. The 0.9 per cent sodium f chlorid extract 
of the meat had a light-pink color. On spectroscopic examination the 
extract showed a fairly distinct narrow band at the left of, and extending 
just over, the D line, and a wider and less distinct band midway between 
the D and the E lines. On the addition of hydrazin hydrate the bands 
at first became more distinct, but after a time disappeared. The fact that 
the absorption bands were not readily affected by hydrazin hydrate and 
that no absorption bands of either hemoglobin or hemochromogen 
appeared after the addition of this reagent indicates that the color of the 
solution was due neither to oxyhemoglobin nor to hematin. The spectrum 
of the solution was, of course, neither that of hemoglobin nor that of hemo¬ 
chromogen. 
Sample incubated por 103 days. —This sample of meat showed the 
brown outer zone and the pink interior common to all of the incubated 
samples. The meat rested in the dish in such a way as to pocket a con¬ 
siderable quantity of meat juice, perhaps 20 c. c., out of contact with the 
air. This juice had a peculiar dark purplish red color and showed the 
