LIFE AND WORK OF FELIX HOPPE-SEYLEB. 547 



coverj of whicli threw light on the chemistry of this important 

 animal substance. Hoppe-Seyler's main work, however, to which 

 we may direct attention, was done upon the red pigment or hasmo- 

 glohin of the blood, npon processes of oxidation in the organism, 

 upon the chemistry of fermentation, and upon chlorophyll. 



It is not too much to say that if all work but Hoppe-Seyler's 

 upon haemoglobin should be obliterated, we would still have nearly 

 all that is known of that important substance. It was Hoppe-Seyler 

 who gave the name haemoglobin, it was he who discovered that it was 

 this substance in the red blood-corpuscles that gave them their power 

 of carrying oxygen, and that hsemoglobin was a definite chemical 

 compound. He discovered the difference between haemoglobin and 

 oxyhsemoglobin. The absorption bands in the spectra and the differ- 

 ence in the spectra of hsemogiobin and oxyhsemoglobin were also dis- 

 covered by him, and he did more than any other one man to apply 

 the spectroscope to the study of the blood pigment. It was Hoppe- 

 Seyler who found that the oxygen combined with and was 

 given up from the hsemogiobin in a molecular and not an atomic 

 form ; he showed that carbonic oxide enters into a stable combination 

 with haemoglobin, and thus explained the peculiarly poisonous nature 

 of this gas. He discovered and named the decomposition products of 

 haemoglobin, methasmoglobin, and hsemochromogen. He showed 

 that haemin was simply the hydrochlorate of hEematin, and pointed 

 out how the hsemogiobin molecule could be taken to pieces and 

 built up by reduction. On the chemistry of haemoglobin he pub- 

 lished no less than thirty papers. 



An interesting discovery made by him was the cause of the 

 sudden death to which men were subject who, after working under 

 compressed air, suddenly returned to the ordinary atmosphere. He 

 showed that under such circumstances the dissolved gases of the 

 blood quickly escaped from solution with fatal results. This dis- 

 covery indicated the proper manner of avoiding such disaster by a 

 gradual return to the normal atmosphere, and has been the means of 

 saving many lives. 



One of the greatest discoveries of Hoppe-Seyler was that the 

 tissues and not the blood are the seat of the oxidations of the body. 

 This was still more convincingly shown later by Pfliiger. By this dis- 

 covery Hoppe-Seyler's attention was attracted to the respiration of 

 protoplasm, with what results we shall shortly see. 



His work on hsemogiobin led Hoppe-Seyler in two directions: 

 one was toward the composition of cells, the other toward respiration. 

 Both paths have been followed with good results. In examining the 

 composition of the red blood-corpuscles of mammals, Hoppe-Seyler 

 discovered that the percentage of phosphoric acid contained in the 



