1897 - 98 .] Dr D. F. Harris on Spectroscopy of Haemoglobin. 203 
it was alkali-haematin, presumably a re-oxidation after the reduc- 
tion due to putrefaction was ended. 
2. Neutral Met-Hcemoglobin (made with K-ferricyanide) was 
unchanged for seventeen days ; at the end of four weeks it was 
HbO, which could he oxidised to Hb0 2 ; at the end of five months 
it was HbO ; at the end of two years it was no longer HbO, there 
was a precipitate, and the supernatant liquid was yellowish. 
Another specimen at the end of two years was still HbO, but after 
three years had become hsemochromogen. 
3. Alkaline Met-Hcemoglobin. — After five months this was 
alkali-hsematin ; at the end of three years it was a yellowish liquid, 
with a shading at F. 
4. Acid Hcematin. — At the end of three months it was intact; 
at the end of two years it showed its characteristic band in the 
red, although the solution had become greenish-yellow ; at the end 
of three years the band in the red was still quite distinct. 
5. Alkali Hcematin at the end of five months was in no way 
altered ; at the end of two years its characteristic absorptions over 
D and in the violet were present, though the colour of the solu- 
tion had become greenish. 
6. Add Hcematoporphyrin. — At the end of three years quite 
unchanged. 
7. Hcemochromogen (made by reducing the KHO alkali- 
haematin with Am 2 S) had a rather curious history. 
By the seventeenth day two specimens of it — one with and 
one without thymol — had become of the most beautiful clear green 
colour, the reaction was alkaline, and there was no precipitate. 
It still showed the two characteristic bands in the green, but had 
in addition a broad area of absorption in the red (to which it owed 
its green colour). 
The pure solution at the end of two years was yellowish, with 
the faintest possible band at F. The solution with thymol had 
become alkali-hoematin at the end of two years, and was still the 
same at the end of three ; it had lost a great deal of its red 
colour. 
8. A Solution of CO-HbO made on 31st January 1895, and 
reduced with Am 2 S on 8th of February, was in two years hsemo- 
chromogen. 
