192 Proceedings of Royal Society of Edinburgh. [sess. 
I mixed 12 c.c. of blood, diluted with half its volume of water, 
with 8 c.c. of '2 per cent, of HC1. — result, met-hsemoglobin ; 
whereas when, for glacial acetic acid, I substituted concentrated HC1. 
in the making of acid hsematin, I obtained typical acid hsematin. 
Gf. M £ Munn (4) and Menzies (5) on this point. I agree with both. 
IY . — The Effect of a Rise of Temperature upon Hcemoglobin. 
The temperature of a water-bath was continuously raised from 
10° C., and the solutions of Hb0 2 taken from it were examined at 
intervals. Up to 40° C. there was no spectroscopic change what- 
ever; between 40° C. and 55° C. a slight turbidity, but no change 
in the bands ; between 60° C. and 65° C. increasing turbidity, but 
no change in the bands ; at 67° C. the bands could just be seen 
amid general haziness, thus showing that the chemical integrity of 
Hb0 2 is not compromised by a temperature as high as 67° C. 
On boiling, the solution became quite opaque, and the Hb0 2 
decomposed, hsematin being precipitated. 
Y . — On Sulph-Hcemoglobin. 
Keduced HbO is usually made by adding Am 2 S, with gentle 
heat, to a solution of Hb0 2 ; in a few seconds it gives the one 
broad band characteristic of the pigment. 
If old filtered Am 2 S be used, no other band appears; but if 
freshly made Am 2 S be used, an additional band, one in the red at 
A.610, appears in the course of a week or so, and persists as long as 
the pigment is spectroscopically intact. There is no doubt this is 
the band of a pigment, due to the presence of the S, named by 
Lankester (6) “ sulph-hsemoglobin.” At first I thought it might be 
due to the presence of the NH 4 , but found this view not tenable, 
for sulph-hsemoglobin can be prepared by passing pure H 2 S through 
diluted blood, when a pigment spectroscopically identical with 
that obtained by Am 2 S is formed. Thus, sulph-hsemoglobin is not 
a pigment per se ; it is reduced haemoglobin, so prepared chemically 
that a band in the red (presumably due to S) is present along with 
the well-known band of HbO. In other words, you cannot have 
this band in the red without also that of reduced HbO ; the reverse 
is, of course, not only possible, but more usual. 
