1897 - 98 .] Dr D. F. Harris on Spectroscopy of Haemoglobin. 205 
arrived at in that paper. He says, “A body very closely re- 
sembling urobilin may by prolonged and complete reduction be 
produced from hsematin in acid solution;” and “ incomplete re- 
duction furnishes a body also resembling urobilin, but which 
immediately reverts to the state of uro-hsematoporphyrin.” This 
latter is an orange pigment, and would “ resemble urobilin.” 
M‘Munn thinks that its red ally and it itself are progressive stages 
in reduction from hsematin. Eichholz did not evidently stop at 
any stage till he reached one resembling urobilin, but it is per- 
fectly possible that, even artificially, one passes through the stage 
of a-hsematoporphyrin.* In the body, if this pigmentary kata- 
bolism to urobilin be disturbed or incomplete, the red or orange 
(a- or /3 - ) hsematoporphyrin may appear in the urine ; sulphonal 
seeming to have a powerful influence in this direction in the case 
of the red or a pigment. 
XV . — The Spectroscopy of Freshly -drawn Blood. 
Under this head I made a large number of observations from 
time to time, but owing to the very great mechanical difficulties 
of examining the blood soon enough, I do not feel justified in 
reporting on any except the following : — 
Blood from the internal jugular of a dog, chloroformed until 
respiration had ceased, gave the one-banded HbO very rapidly 
changing to Hb0 2 upon oxidation. 
A large dog, chloroformed till respiration ceased, yielded from 
int. jugular HbO, from left ventricle Hb0 2 . 
A cat, suddenly killed by a blow on the head, gave with blood 
of right ventricle HbO, with blood of left ventricle Hb0 2 . 
In a month-old rabbit, chloroformed till respiration ceased, 
Blood of right ventricle was HbO with one band rapidly becoming 
two on oxidation ; from internal jugular HbO also. 
So far as I am entitled to form an opinion, I confirm M‘Munn 
in saying, “the blood in the right side of the heart and in the 
veins is reduced as soon as the animal has ceased to breathe, but 
the Hb0 2 of the blood in the left side of the heart and aorta does 
not become reduced for some time after death” (12); how long 
* I suggest this name instead of Meio-de-oxy-hsematoporphyrin, which 
denotes a particular view. 
