﻿12 



INDIAK^A UNIVEESITY 



already entered into some sort of combination with the proteids 

 themselves. This is what I believe actually occurs. In this con- 

 nection may be recalled the actiou of oxalates, Avhich precipitate the 

 free calcium of the blood, but apparently do not form proteid 

 combinations, for addition of a slight excess of calcium chloride 

 again establishes the conditions requisite for coagulation of the 

 blood. It must, of course, not be forgotten that the addition of 

 a two per cent solution of the disodium hydrogen phosphate (in 

 any amount up to an equal volume) to normal blood does not 

 prevent coagulation. 



It is generally assumed that the cyanides prevent coagulation 

 by inhibiting the action of the ferments concerned in clot forma- 

 tion. If this be the whole truth (which I am inclined to doubt), 

 then the above results would seem to indicate that the action of 

 uranium is much more extensive than that of the cyanides so far 

 as the inhibition of clot formation is concerned. And uranium 

 certainly acts differently from several of the other inorganic com- 

 pounds which are ordinarily used to prevent clot formation. 



When a cyanide is added to drawn blood outside the body, a 

 bright red color is at once produced. This is usually described 

 as being the same color as that possesssed by pure arterial blood. 

 In a similar manner if a small quantity (one-twentieth volume of 

 two per cent) of sodium uranium tartrate solution be added in 

 the presence of oxygen or air to freshly dra^vn blood, this blood 

 will also rapidly take on a bright red color resembling that of ar- 

 terial blood. To the naked eye cyanide blood and uranium blood 

 look very much alike. It is to remembered, however, that retinal 

 fatigue, and the constant color variations which are generally to 

 be readily observed in freshly drawn blood when exposed to the 

 air (and particularly if shaken or stirred), render close color dis- 

 tinctions in such cases as this very dilScult to make. It would 

 appear that the presence of a certain amount of available oxygen 

 is absolutely necessary for this color reaction to take place when 

 the blood has been treated with uranium. In order to test this 

 point I tried the following experiment. In an etherized dog the 

 external jugular vein was dissected out and clamped with a ser- 

 resfin. The venous blood (dark) soon accumulated in the vein 

 above the serresfin, A small glass-barreled hypodermic syringe 

 was then partly filled with uranium solution, care being taken to 

 exclude all air bubbles. The point of the syringe was then passed 

 into the swollen vein and blood was drawn directly into the syringe 

 until the barrel was three-fourths full. The point was then with- 



