1916 



Langdon; on Carbon Monoxide 



239 



shown by the series of photographs given in plate 43. The characteristic 

 absorption spectrum of dilute normal blood, that is, haemoglobin, shows two 

 dark bands in the yellow and green region (see E, plate 42). D of the 

 same plate shows the absorption spectrum of the same blood after it has 

 been treated with ammonium sulfide and the oxyhaemoglobin reduced; the 

 two dark bands which have disappeared are replaced by a single, less clearly 



A 

 B 

 C 



D 

 E 

 F 



Known CO 



Known CO+(NHJ, S 



Kelp Gas+(NHJ, S 



Normal Blood+(NHJo S 



Normal Blood 



Kelp Gas 



PLATE 43 



marked, band. As shown in A, the absorption spectrum of blood which 

 has been treated with known carbon monoxide is almost identical with 

 that of normal oxyhaemoglobin (£^), but on treatment with ammonium sul- 

 fide the carbon monoxide haemoglobin is not reduced and there is no change 

 in the absorption spectrum {see B). Samples of the dilute blood treated 

 with kelp gas gave the absorption spectrum shown in F and which is similar 

 to A and B and was not changed (compare C) by attempted reduction 

 with ammonium sulfide. Hempel (Methods of Gas Analysis: Dennis' 

 translation of 3rd edition, page 211) says: "This reaction is of especial 

 significance, because the carbon monoxide cannot be confounded with an- 

 other gas." 



A guinea pig placed in a vessel through which kelp gas was passing 

 died in less than ten minutes. Death was not due to the absence of oxy- 

 gen, for the gas contained about 18 per cent of oxygen, and fresh gas 

 was being continuously forced through the vessel. Postmortem examination 

 of the body showed the characteristic appearances associated with carbon 

 monoxide poisoning. The nose, lips, and conjunctivae had assumed a red 

 color. The blood was of a bright scarlet color which seemed permanent, 

 for it was still unchanged after three weeks' exposure in an open evapor- 



