S ( '/./'//( )-ME 111. EMOGLOBIN (?). 249 
action of 11C.X on oxyhaemoglobin, and by N"awrocki and Lankester as pro- 
duced when KCN acts upon blood, especially with the aid of gentle heat, and 
which has generally been held to he a compound of cyanogen and hsematin 
(cyanhaematin). 
Szigeti 1 maintains that Robert's cyanogenmethaemoglobin is in reality 
cyanhaematin, the first step in the action of HCX being to split up the 
met haemoglobin molecule into hsematin and an albuminous substance. I do 
not, however, take this view, and, in spite of the evidence which Kohert has 
adduced being in many respects incomplete, I am inclined to think that the 
view which he has advanced is correct. In the first place, the certain existence 
of compounds of the nitrites with methaemoglobin affords presumptive 
evidence of the strongest kind that similar compounds with such bodies 
as cyanogen, hydrocyanic acid, and cyanides exist; in the second, the almost- 
instantaneous action of solutions of hydrocyanic acid of phenomenal dilu- 
tion renders it highly improbable that the action of hydrocyanic acid on 
methaemoglobin is one in which decomposition into hsematin is a preliminary 
stage. 
There can be no question that HCX acting in the cold, and, for a short 
time upon, blood or on solutions of oxyhaemoglobin, produces no change in the 
spectrum, and it is against all experience and analogy from the action of other 
dilute acids on either oxyhemoglobin or methaemoglobin to conclude that 
solutions of HCX of extraordinary dilution should be able — and almost instan- 
taneously—to split up the oxyorthomethamioglobin molecule. Robert has 
found that a solution containing 0-000003 grm. of HCX is able to produce the 
characteristic change in 1 c.c, of a 1 per cent, solution of methaemoglobin. 
He has further shown that his assumed cyanogenmethaenioglobin contains 
HCX which can be recovered from it without loss by distilling with sulphuric 
acid. 
CO-methsemoglobin. — According to Weyl and v. Anrep,'- this com- 
pound is produced when aqueous solutions of iodine and potassium iodide, 
or solutions of potassium permanganate, continue to act upon a solution of 
CO-haemoglobin for several days. This body is said to retain the red colour 
of CO- haemoglobin, and to present the same absorption-bands in its spectrum. 
I fail to understand the grounds for believing in its existence. 
Sulpho - methaemoglobin. — This hypothetical body was believed by 
Hoppe-Seyler 3 to he the cause of the green coloration observed on the 
surface of putrefying organs. 
Sulphuretted hydrogen has no action on reduced haemoglobin. When 
acting in small quantities on neutral solutions of pure oxyhaemoglobin, it 
reduces these. If, simultaneously, a stream of sulphuretted hydrogen and 
oxygen be passed through blood or neutral solutions of pure oxyhaemoglobin, 
the solution assumes a green colour in thin, and a red colour in thick layers, 
and becomes turbid. These solutions are characterised by the presence of two 
absorption-bands in the red, one on the red side of, but quite close to, C ; the 
other is about midway between C and D, the two bands being united together 
by a shadow. 
It appears to me that there is not the slightest ground for believing 
that the phenomena above described are due to a definite body, — "sulpho- 
1 "Ueber Cyanhamatin," Vrttjschr. f. gerichlt. u. off. Med., Berlin, Supp. Bd. vi. 
S. 9-35. I only know this paper from the abstract by Andreasch in Jahresb. u. d. Fortschr. 
d. Thier-Chem., Wiesbaden, 1883, Bd. xxiii. S. 620. 
2 "Ueber Kohlenoxyd-Hamoglobin," 1. Oxydation von CO-Hb zu Metli-Hb, Arch./. 
Physiol., Leipzig, 1880^ S. 227-240. 
3 Centralbl. f. d. med. Wissensch., Berlin, 1868, No. 28; "Ueber die Einwirkung 
des Schwefehvasserstoffs auf d. Blatfarbstoff," Med.-chem. Untersuch., Berlin, S. 651 ; 
Araki, " Schwefelmethsemoglobin," Ztschr.f. physiol. C/iem., Strassbnrg, 1890, Bd. xi. S. 
412-416. 
