1902.] and Physical Properties of Haemoglobin, 



83 



width of 5 mm. and contained 2'5 c.c. of a 1 per cent, solution of 

 OoHb, complete precipitation and transfer occurs within 60 minutes. 



4. On reversing the direction of the current by means of a commu- 

 tator, the haemoglobin returns again in the direction of the positive 

 current into the original cell from which it started. 



5. The author adduces evidence which proves that the precipitated 

 colloidal, but yet perfectly soluble, haemoglobin represents the unde- 

 composed molecule of the blood colouring matter. 



6. The probable nature of the process which occurs under the 

 influence of the current is discussed, as well as the character of the 

 process which leads to the transfer of the haemoglobin in the direction 

 of the positive current. This process the author considers to be of the 

 same nature as the phenomena studied by Quincke under the name of 

 electro-endosmose. 



7. The author directs special attention to the importance of the 

 facts which he has elicited in reference to the colloidal yet soluble 

 form of oxy-haemoglobin. He points out that all which has been 

 said with regard to oxy-haemoglobin applies to CO-haemoglobin. 



A typical colloid in the sense of its absolute indiffnsibility through 

 animal membranes and parchment paper, oxy-haemoglobin differs, how- 

 ever, from most colloids in the facility with which it crystallises. 

 Hitherto we have known it in its crystalline condition and in solution 

 in water. Now in its third or colloidal form the analogy with such a 

 colloid as silicic acid is rendered complete. 



The discovery of this form of haemoglobin enables us to form a con- 

 ception of the state in which the blood colouring matter is probably 

 contained in the blood corpuscles. We have known that the amount 

 of haemoglobin contained in the corpuscles is so large that in most 

 animals at least the whole of the water of the blood would not be 

 sufficient to dissolve it. It was perfectly obvious, therefore, that it 

 did not exist in the corpuscles in a state of solution, and the opinion 

 has generally been held that these contained some unknown compound 

 of oxy-haemoglobin with a constituent of the stroma. It seems highly 

 probable that in the red blood corpuscle haemoglobin may be merely 

 present in. its colloidal form. 



Finally the auther points out that the remarkable facility with which 

 the new colloidal form of haemoglobin traverses such permeable mem- 

 branes as the animal membranes and even parchment paper, when its 

 solutions are subjected to electrolysis, suggests to physiologists the 

 possibility that certain of the phenomena of absorption in the animal 

 body may be closely connected with electromotive changes in the 

 tissues concerned. 



