594 
DR. A. GAMGEE ON THE ACTION OE NITRITES ON BLOOD. 
II. indicates the position occupied by several of the bright lines of the metals in rela- 
tion to the millimetre scale of the spectroscope used. 
Koc 30 
Lia 43 
Na 60 
Th 75 
Iri 110 
Kb/3 136 
Kba 137 
K/3 152 
III. indicates the absorption-spectrum of oxidized haemoglobin as seen in relation to 
the millimetre scale of my instrument. 
a . . . 60-65 
/3 . . . 72-78. 
IV. indicates the absorption-band of reduced haemoglobin (purple cruorine). 
7 . . . 65-74. 
V. indicates the spectrum of blood which has been treated with nitrites. The crys- 
tals of the nitrite compound of haemoglobin also exhibit the same spectrum. 
a . . . 60-65 (very faint). 
(3 . . . 72-78 (very faint). 
& . . . 49-51. 
VI. indicates the absorption-bands of the compounds of nitrite with haemoglobin after 
the addition of ammonia. 
a' 56-59. 
(3 60-65T 
a 72-78/ 
blacker and more sharply defined than in V., not so much so as in III. 
The spectroscope which I chiefly employed in this research was one with a single prism, 
constructed by Desaga, of Heidelberg. I ascertained exactly the positions of the most 
characteristic lines of the metals in relation to the millimetre scale of the instrument. 
The position of the absorption-bands described by me will be better seen by comparison 
with the drawing, in which the position of the bright lines of the metals is marked. 
I have also, for comparison, inserted spectra of oxidized and reduced cruorine, in which 
the position of the absorption-bands of these substances is seen in relation to the milli- 
metre scale of my instrument. In the case of the oxidized colouring-matter, I shall 
distinguish the absorption-bands in the yellow and green as a and (3 respectively ; that 
of reduced cruorine I shall refer to as 7. 
Obs. I. A solution of dehbrinated Ox’s blood was made by diluting 5 cub. centims. 
to the volume of one litre with distilled water. The solution was placed for examination 
