LIFE AND WORK OF FELIX HOPPE-SEYLER. 549 



have access, putrefying fluids, like protoplasm, are able to oxi- 

 dize completely tlie most resistant substances, side by side mth 

 strong reductions. Hoppe-Seyler noticed that if animal sub- 

 stances be allowed to putrefy in vessels deprived of air, intense reduc- 

 tions ensue, hydrogen gas is often set free, and the whole chemical 

 transformation is entirely different from that which the same sub- 

 stances undergo if a current of air be constantly forced through 

 the fluid. In the latter case the transformations are oxidations, and 

 finally are of a most complete kind, little else than nitrates, car- 

 bonates, and sulphates being left. If a putrefying fluid be allowed 

 to stand exposed to air, Hoppe-Seyler discovered that at the surface 

 the most intense oxidation ensued, while in the depths there were 

 equally intense reductions. He found, further, in studying the fer- 

 mentation of fibrin and calcium lactate, as well as other substances, 

 that if no oxygen were present large quantities of hydrogen gas were 

 evolved, if air were present no hydrogen was evolved. He imme- 

 diately recognized in nascent hydrogen a reducing agent capable of 

 causing the strong reductions and of splitting the oxygen molecule, 

 thus indirectly causing oxidation. He suspected that nascent hydro- 

 gen would combine with one atom of the oxygen molecule to form 

 water, setting the other atom free, and experiment fully confirmed 

 this hypothesis. If palladium be heated in a stream of hydrogen, it 

 combines with the latter. If it now be brought into water, the 

 hydrogen is liberated in the atomic state. Hoppe-Seyler found that 

 palladium loaded with hydrogen would carry out oxidations and 

 reductions similar to those of putrefying fluids. H such a palladium 

 mass be half immersed in water containing benzol, haemoglobin, 

 potassium iodide, or indigo, in the depths of the fluid strong reduc- 

 tions ensue, with at the surface equally violent oxidations. In such 

 circumstances oxyhemoglobin at the surface is transformed into 

 methseglobin, benzol to phenol, indigo to indigo white at the bottom 

 and indigo yellow at the surface, and iodine is liberated from its 

 potassium combination. Hoppe-Seyler believed that in protoplasm 

 a substance was present which acted somewhat like potassium 

 hydrate or the ferments in the putrefying masses, causing a saponifi- 

 cation, and at the same time a transference of an oxygen atom from 

 a hydrogen to a carbon atom, with the liberation of nascent hydro- 

 gen, or other reducing substance. The nascent hydrogen, in the man- 

 ner already indicated, caused both intense reductions as well as oxida- 

 tions. In this manner, as is well known in chemical processes outside 

 of the cell, many syntheses and poljnnerizations can be brought 

 about, and it would seem necessarily to result, in protoplasm, in just 

 such a constant rearrangement of molecules as is imagined constantly 

 to be transpiring there. Hoppe-Seyler believed that the oxygen 



