HEMOGLOBIN 165 



as compared with the solar spectrum. Compared with the spectrum 

 shown in the frontispiece. 



2. Hemoglobin. The oxygen can be driven out from the oxyhemoglobin 

 by adding to the above samples a few drops of ammonium sulphide and 

 gently warming. Re-examine with the direct- vision spectroscope and map 

 as before. 



3. Carbon-monoxide Hemoglobin. Pass a stream of ordinary illumi- 

 nating gas through the dilutions of hemoglobin. The carbon monoxide 

 of the gas will form a compound with the hemoglobin, which now turns a 

 bright scarlet color. When examined with the spectroscope, the absorp- 

 tion bands are found to be very similar to those of oxyhemoglobin. How- 

 ever, map the spectrum to the scale as usual. Add the reducing agent, 

 warm, and shake vigorously and re-examine. It is very difficult to break up 

 the combination of hemoglobin with carbon monoxide, hence the poisonous 

 action of this gas. 



