SULPHO-METH^EMOGLOBIN (?). 249 



action of HCN on oxy haemoglobin, and by Nawrocki and Lankester as pro- 

 duced when KCN acts upon blood, especially with the aid of gentle heat, and 

 which has generally been held to be a compound of cyanogen and hsematin 

 (cyanhsematin). 



Szigeti l maintains that Kobert's cyanogenmethsemoglobin is in reality 

 cyanhaematin, the first step in the action of HCJST being to split up the 

 methsemoglobin molecule into hsematin and an albuminous substance. I do 

 not, however, take this view, and, in spite of the evidence which Kobert 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 haematin is a preliminary 

 stage. 



There can be no question that HCN acting in the cold, and, for a short 

 time upon, blood or on solutions of oxyhsemoglobin, produces no change in the 

 spectrum, and it is against all experience and analogy from the action of other 

 dilute acids on either oxyhaemoglobin or metheemoglobin to conclude that 

 solutions of HCN of extraordinary dilution should be able and almost instan- 

 taneously to split up the oxyorthomethsemoglobin molecule. Kobert has 

 found that a solution containing 0*000003 grin, of HCN is able to produce the 

 characteristic change in 1 c.c. of a 1 per cent, solution of methsemoglobin. 

 He has further shown that his assumed cyanogenmethaemoglobin contains 

 HCN which can be recovered from it without loss by distilling with sulphuric 

 acid. 



CO-methsemoglobin. According to Weyl and v. Anrep,' 2 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-hsemoglobin for several days. This body is said to retain the red colour 

 of CO-hsemoglobin, and to present the same absorption-bands in its spectrum. 

 I fail to understand the grounds for believing in its existence. 



Sulpho - methsemoglobin. This hypothetical body was believed by 

 Hoppe-Seyler 3 to be 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 oxyhsemoglobin, 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 Cyanliamatin," Vrtljschr. f. gerichlt. u. off. Mcd., Berlin, Supp. Bd. vi. 

 S. 9-35. I only know this paper from the abstract by Andreasch in Jahresb. u. d. Fortschr. 

 d. Thicr-Chem. , Wiesbaden, 1883, Bd. xxiii. S. 620. 



2 "Ueber Kohlenoxyd-Hamocrlobin," 1. Oxydation von CO-Hb zu Meth-Hb, Arch.f. 

 Physiol., Leipzig, 1880, S. 227-240. 



3 CentralU. f. d. med. Wis&ensch., Berlin, 1868, No. 28; "Ueber die Einwirkung 

 des Schwefelwasserstoffs auf d. Blutfarbstoff," Med.-chem. Untersuch., Berlin, S. 651 ; 

 Araki, " Schwefelmethsemoglobin ," Ztschr. f. physiol. Chem., Strassbnrg, 1890, Bd. xi. S. 

 412-416. 



