Oct. 2,1916 Formation of Hematoporphyrin in Ox Muscle 43 
following spectrum: A heavy narrow band, with sharply defined edges, 
immediately at the left of the D line; and a second band, two to three 
times as wide as the first band, but not quite so heavy, and with less 
sharply defined edges, midway between the D and the E lines.. The addi¬ 
tion of hydrazin hydrate did not affect the color or spectrum of the 
solution. 
Sample incubated for 123 days. —This sample had the usual brown 
outer zone and pink interior. When ground and extracted with water, 
the pink inner portion yielded a light straw-colored extract tinged with 
pink. The following spectrum was observed: A fairly heavy band im¬ 
mediately at the left of the D line; and a lighter and wider band between 
the D and the E lines. 
The extract was tested for bile pigments by means of Hammarsten's 
test, with negative results. 
Sample incubated for 220 days. —The brown outer zone had ex¬ 
tended to a depth of nearly an inch, leaving only a small inner portion 
that was pink. The pink-colored portion when ground and extracted 
with water yielded a light straw-colored extract that showed the following 
spectrum: A heavy narrow band just at the left of the D line; and a wider, 
heavy band midway between the D and the E lines. The addition of 
hydrazin hydrate did not affect the color or the spectrum of the solution. 
A summary of the observations which have been made concerning the 
effect of autolysis upon the natural red color of ox muscle leads to the 
conclusion that the pink or purplish red color which was developed in 
the interior of the samples of muscular tissue and in the exuded juice that 
had been protected from the air was due to hematoporphyrin that had 
been formed by the reduction of oxyhemoglobin. This conclusion is 
supported by the following evidence: (1) The spectrum of the color and 
its behavior toward reducing agents correspond with those of hemato¬ 
porphyrin; (2) the color was formed only in the absence of oxygen, a 
condition necessary for the formation of hematoporphyrin, and it was 
destroyed on exposure to the air; (3) conditions under which hemato¬ 
porphyrin is formed in the body indicate that this compound probably 
results from the action of certain intracellular enzyms upon free hemo¬ 
globin, and it is reasonable to expect that a similar change might occur in 
the coloring matter of muscular tissue during autolysis, provided that 
suitable conditions are maintained; (4) the pink to purplish red color 
developed in the tissue and exuded juice during autolysis is characteristic 
of hematoporphyrin. In all essential properties, the substance which im¬ 
parted the pink to ’purplish red color to the interior of the incubated meat 
samples, and to the exuded meat juice that was protected from the air, 
correspond to hematoporphyrin. 
